FAQ about billing

Why am I unable to purchase ECS instances?

You may be unable to purchase ECS instances due to one of the following reasons:

• You have not completed real-name verification. Before you can purchase ECS instances in a region inside the Chinese mainland, you must complete real-name verification.

• The number of vCPUs required by the ECS instances that you want to create exceeds the remaining vCPU-based quota for the selected instance type in your account.

• The selected instance type is unavailable for purchase in the selected region because you reached the maximum number of instances of the instance type in the region. Try again later or go to the Instance Types Available for Each Region page to view instance types available in each region.

How are invoices issued for ECS instances?

You can request invoices for your ECS instances. An invoice is issued based on your monthly statement. You can go to the Expenses and Costs console to request an invoice.

How is the refundable amount for an instance configuration downgrade calculated?

Remaining value: The value of a subscription ECS instance decreases over its subscription period. If you cancel the subscription for an instance, the remaining value of the instance can be refunded to you. For example, assume that you purchased a 30-day subscription instance at the price of USD 30. If you cancel the subscription for the instance after the instance was in use for 10 days, the remaining value of the instance is USD 20 and USD 20 will be refunded to you.

If you used a currency other than USD to pay for the instance, the amount on the instance purchase order was converted to your payment currency at the exchange rate at the time of payment. This exchange rate will be considered during the calculation of the instance remaining value. Different from the price difference-based method, the ratio-based method ensures that refunds are made based on the exchange rate that was in effect at the time of payment. This prevents the amounts refunded for instance configuration downgrades from being affected by fluctuations in the exchange rate.

The following examples demonstrate how to calculate the refundable amount in MYR for instance configuration downgrades based on ratios:

• Example 1: The configurations of a new instance are downgraded.

  Assume that on the first day of a calendar month, you placed an order to purchase a 30-day subscription instance (Instance A) and the order amount was USD 30. The MYR to USD exchange rate was 1:10 at the time of your purchase, and you paid MYR 300 in total. On the 11th day of the calendar month, you initiate a configuration downgrade for the instance. The price of the new instance configurations is USD 0.5 per day. To calculate the refundable amount for the downgrade, perform the following steps:

  1. Calculate the remaining value M of Instance A.

     M = MYR 300 × (30 days -10 days)/30 days = MYR 200

  2. Calculate the refund ratio R.

     R = (USD 1 per day - USD 0.5 per day)/USD 1 per day = 1/2

  3. Calculate the refundable amount.

     Refundable amount = M × R = MYR 200 × 1/2 = MYR 100

  In this example, Alibaba Cloud will refund MYR 100 for the instance configuration downgrade.

• Example 2: The configurations of a new instance are upgraded and then downgraded.

  Assume that on the first day of a calendar month, you placed an order to purchase a 30-day subscription instance (Instance B) and the order amount was USD 30. The MYR to USD exchange rate was 1:10 at the time of your purchase. You paid MYR 300 in total. On the 11th day of the calendar month, you upgraded the configurations of the instance. The price of the new instance configurations was USD 2 per day. The MYR to USD exchange rate was 1:11 at the time of upgrade. You paid the price difference P between the original and new instance configurations. P is calculated by using the following formula: P = (USD 2 per day - USD 1 per day) × (30 days - 10 days) × 11 = MYR 220. On the 21st day of the calendar month, you initiate a configuration downgrade for the instance. The price of the new instance configurations is USD 0.5 per day. To calculate the refundable amount, perform the following steps:

  1. Calculate the remaining value M of Instance B.

     The configurations of the instance are upgraded. The remaining value of the instance consists of the remaining value M1 from the instance purchase and the remaining value M2 from the configuration upgrade. M1 and M2 are calculated by using the following formulas:

     • M1 = USD 30 × (30 days -20 days)/30 days × 10 = MYR 100

     • M2 = USD 20 × (20 days -10 days)/20 days × 11 = MYR 110

     M = M1 + M2 = MYR 210

  2. Calculate the refund ratio R.

     R = (USD 2 per day - USD 0.5 per day)/USD 2 per day = 3/4

  3. Calculate the refundable amount.

     Refundable amount = M × R = M1 × R + M2 × R = MYR 100 × 3/4 + MYR 110 × 3/4 = MYR 157.5

  In this example, Alibaba Cloud will refund MYR 157.5 for the instance configuration downgrade.

Why is the refundable amount for an instance configuration downgrade less than the amount I expected?

If you purchased the instance at a discounted rate or if the instance price changed before the downgrade, the refundable amount may be less than the amount you expected.

For example, assume that you purchased a 30-day subscription instance at the price of USD 1 per day, and that the MYR to USD exchange rate was 1:10 at the time of your purchase. You paid MYR 300 for the instance. 10 days later, you initiate a configuration downgrade for the instance, and the price of the new instance configurations is USD 0.5 per day. The refundable amount is MYR 100 as calculated based on the original price of USD 1 per day. However, if you purchased the instance at a discounted rate or if the instance price changed before the downgrade, the refundable amount is calculated based on the non-discounted or new instance price. For example, if the instance price changed to USD 0.7 per day before the downgrade, the refundable amount is calculated by using the following steps:

1. Calculate the remaining value M of Instance A.

   M = MYR 300 × (30 days -10 days)/30 days = MYR 200

2. Calculate the refund ratio R.

   R = (USD 0.7 per day - USD 0.5 per day)/USD 1 per day = 1/5

3. Calculate the refundable amount.

   Refundable amount = M × R = MYR 200 × 1/5 = MYR 40

In this example, the actual refundable amount is MYR 40 instead of MYR 100.

What is a savings plan?

A savings plan is a plan that provides discounts over pay-as-you-go pricing in exchange for a commitment to use a consistent amount (measured in USD per hour) of resources over a one-year or three-year period. After you purchase a savings plan, your hourly usage of pay-as-you-go instances is covered up to the commitment of the savings plan with the Savings Plan discount applied. For more information, see Overview.

What are the benefits of savings plans?

• Flexible price levels and payment: Savings plans are available for purchase for as little as one cent and have no price limits. Savings plans can be paid in installments to minimize the impact on your cash flow.

• Cost-effective: Savings plans can significantly reduce costs and provide discounts for pay-as-you-go resources of up to 76% off.

• Easy to manage: A single savings plan can be applied to pay-as-you-go ECS instances or elastic container instances across different regions, instance types, and accounts.

What is the hourly commitment of a savings plan?

When you purchase a savings plan, you commit to a usage duration and an amount of spending. The hourly commitment is the minimum number of resources (measured in USD) that you commit to use per hour. In the hourly bills that are generated, the charges for the number of resources that you committed to in the savings plan are discounted. If you select the Partial Upfront payment option for your savings plan, you pay 50% of your hourly commitment when your hourly bill is less than your hourly commitment. If you select the No Upfront payment option for your savings plan, you pay 100% of your hourly commitment when your hourly bill is less than your hourly commitment. For information about how to select an appropriate hourly commitment, see Purchase and apply savings plans.

When the number of instances to which a savings plan can be applied is not an integer, how does the savings plan work?

If your savings plan can be applied to 38.22 instances per hour and you have 39 instances running, the hourly fees for 38 of your instances are fully covered by your savings plan. For one of your instances, 22% of the hourly fees are covered by your savings plan, and the remaining 78% of the hourly fees are paid at regular pay-as-you-go rates. If you have 38 instances running, the coverage for 0.22 instances per hour is wasted in the savings plan.

Which types of savings plans are available?

General-purpose savings plans can provide more flexibility than ECS compute savings plans, but ECS compute savings plans provide higher discounts and cost savings. For more information, see Overview.

Which payment options do savings plans support?

Savings plans support three payment options: All Upfront, Partial Upfront, and No Upfront. The discounts that you receive vary based on the durations and payment options of savings plans. You receive the largest discount when you purchase a three-year All Upfront savings plan. The following combinations of different durations and payment options are ranked from largest to smallest discount: three-year Partial Upfront > three-year No Upfront > one-year All Upfront > one-year Partial Upfront > one-year No Upfront. For more information, see Savings plans.

Where do I view the recommendation and buy pages for savings plans?

• Method 1:

  You can directly access the savings plan buy page to purchase a savings plan. Alternatively, you can access the Savings Plan Purchase Scheme Calculation page in the Expenses and Costs console to obtain purchase recommendations. Savings plans are recommended based on your specified conditions, such as historical consumption of a specified period of time, savings plan type, and payment option.

• Method 2:

  Log on to the ECS console. In the left-side navigation pane, choose Deployment & Elasticity > Savings Plans.

How do I query the discount offered in a savings plan?

You can go to the Discount Details page in the Expenses and Costs console to query the discount offered by a savings plan on pay-as-you-go pricing.

How do I query the cost savings provided by a savings plan?

You can go to the Savings Plan page to view the cost savings provided by a savings plan, including the total, annual, and monthly savings.

Can I have multiple savings plans in effect at the same time?

Yes, you can purchase multiple savings plans and use them together. The system automatically selects the optimal savings plan to apply.

Can I purchase reserved instances after I purchase savings plans?

Yes, you can purchase reserved instances after you purchase savings plans. However, reserved instances take precedence over savings plans to be applied to pay-as-you-go instances.

Can I purchase SCUs after I purchase savings plans?

Yes, you can purchase storage capacity units (SCUs) after you purchase savings plans. However, SCUs take precedence over savings plans to be applied to pay-as-you-go instances.

After I purchase savings plans, can I upgrade the instance types of the instances to which the savings plans are applied?

No, you cannot upgrade the instance types of the instances to which the savings plans you purchase are applied. You can purchase additional savings plans for the instance types to which you want to upgrade.

Do savings plans provide reserved resources?

Can savings plans be applied to preemptible instances?

No, savings plans cannot be applied to preemptible instances.

What happens if my savings plans expire?

When your savings plans expire, the discounts provided by your savings plans are no longer available. Eligible pay-as-you-go instances are billed at their regular prices. The pay-as-you-go instances to which your savings plans have already been applied are not released. The expiration of savings plans does not affect your business.

Do reserved instances provide reserved resources?

Zonal reserved instances provide reserved resources, but regional reserved instances do not.

What operating systems do reserved instances support?

Reserved instances support Windows and Linux. For example, you can purchase a reserved Linux instance and then apply this reserved instance to pay-as-you-go Linux instances that match the attributes of the reserved instance regardless of the image type, such as public images, custom images, shared images, or Alibaba Cloud Marketplace images.

To apply a reserved instance to pay-as-you-go instances that were created from Bring Your Own License (BYOL) images, submit a ticket.

Which instance families do reserved instances support?

Can reserved instances be applied to preemptible instances?

No, reserved instances cannot be applied to preemptible instances.

Can the instance families of reserved instances be changed?

No, the instance families of reserved instances cannot be changed.

To what scenarios are zonal reserved instances applicable?

We recommend that you purchase zonal reserved instances when you have clear requirements to reserve resources.

To what scenarios are regional reserved instances applicable?

We recommend that you purchase regional reserved instances if you want to have a higher degree of zone flexibility or instance size flexibility.

How is the zone flexibility of reserved instances applied?

Only regional reserved instances provide zone flexibility. Example:

Assume that you are running the following pay-as-you-go instance:

One ecs.c5.xlarge Linux instance in Qingdao Zone B. This instance is named C5PAYG-b.

Assume that you purchased the following reserved instance:

One regional ecs.c5.xlarge reserved instance in the China (Qingdao) region. This instance is named C5RI.

C5RI is matched to C5PAYG-b.

You release C5PAYG-b and create another pay-as-you-go Linux instance of the same instance type named C5PAYG-c in Qingdao Zone C. C5RI is matched to C5PAYG-c.

How is the instance size flexibility of reserved instances applied?

Only regional reserved instances provide instance size flexibility. Examples:

Assume that you have one regional ecs.g5.4xlarge reserved instance. The reserved instance can be applied to one ecs.g5.4xlarge pay-as-you-go instance, two ecs.g5.2xlarge pay-as-you-go instances, or four ecs.g5.xlarge pay-as-you-go instances.

Assume that you have a one-year regional ecs.g5.xlarge reserved instance. The reserved instance can be applied to offset the hourly fees of an ecs.g5.xlarge pay-as-you-go instance or 50% of the hourly fees of an ecs.g5.2xlarge pay-as-you-go instance for one year.

Do zonal reserved instances provide instance size flexibility?

No, zonal reserved instances do not provide instance size flexibility. A zonal reserved instance can be applied only to pay-as-you-go instances of the same instance type.

Do zonal reserved instances provide zone flexibility?

No, zonal reserved instances do not provide zone flexibility. A zonal reserved instance can be applied only to pay-as-you-go instances in the same zone as it.

Can a zonal reserved instance be changed into a regional reserved instance?

Yes, a zonal reserved instance can be changed into a regional reserved instance. The scope of a reserved instance can be changed in the following ways:

• From a zone to a region

• From a region to a zone

• From one zone to another zone in the same region

Can the scope of a reserved instance be changed from one region to another?

No, the scope of a reserved instance cannot be changed from one region to another. For example, assume that you have a zonal reserved instance scoped to Hangzhou Zone B. You can change the instance scope to another zone in the China (Hangzhou) region or change the instance into a regional reserved instance scoped to the China (Hangzhou) region. However, you cannot change the scope of the instance to a zone in another region or change the instance into a regional reserved instance scoped to another region.

Can reserved instances be used across accounts?

No, reserved instances cannot be used across accounts.

Can reserved instances be used to offset the storage and network usage fees of pay-as-you-go instances?

No, reserved instances cannot be used to offset the storage or network usage fees of pay-as-you-go instances. Reserved instances are applied to offset the fees for vCPUs and memory of pay-as-you-go instances. Windows reserved instances can also offset image fees.

Can I configure a reserved instance to be applied to a specific pay-as-you-go instance?

No, you cannot configure a reserved instance to be applied to a specific pay-as-you-go instance. When multiple pay-as-you-go instances match the attributes of a reserved instance, the reserved instance is applied based on the optimized matching scheme.

How are reserved instances billed?

Reserved instances are billed separately and support the All Upfront, Partial Upfront, and No Upfront payment options.

The term of a reserved instance begins at the time when the instance is purchased. You are charged based on the payment option that you selected, regardless of whether the reserved instance is matched to pay-as-you-go instances. The All Upfront option is the most cost-effective. For more information, see Reserved instances.

When does a reserved instance take effect after it is purchased?

After I modify, split, or merge a reserved instance, when does the operation take effect?

When reserved instances are modified, split, or merged, new reserved instances are generated and the original ones become invalid. The new reserved instances take effect and the original ones become invalid at the start of the hour during which the modification, splitting, or merging operation was performed. For example, assume that you split one ecs.g5.2xlarge zonal reserved instance RI1 into two zonal ecs.g5.xlarge reserved instances RI2 and RI3 at 13:45:00 on February 26, 2019. At 13:00:00 on February 26, 2019, RI1 becomes invalid and RI2 and RI3 take effect. Starting from 13:00:00 on February 26, 2019, the instance type eligible for resource reservation and billing discounts is ecs.g5.xlarge, no longer ecs.g5.2xlarge. If RI2 and RI3 are matched to pay-as-you-go instances immediately after they take effect, RI2 and RI3 are applied to offset the hourly fees of ecs.g5.xlarge pay-as-you-go instances starting from 13:00:00 on February 26, 2019.

Why is the No Upfront payment option not displayed on the buy page?

The availability of this option depends on your ECS usage.

Can the payment option of a reserved instance be changed?

No, the payment options of reserved instances cannot be changed.

Can reserved instances be resold?

No, reserved instances cannot be resold.

Can I use reserved instances to cover the image fees of pay-as-you-go Windows instances?

Yes, Windows reserved instances can be applied to offset the image fees of pay-as-you-go Windows instances. This is because Windows reserved instances already include Windows images at no additional cost.

Can I use Linux reserved instances to offset the image fees of pay-as-you-go Linux instances?

No, Linux reserved instances cannot be applied to offset the image fees of pay-as-you-go Linux instances.

Are the consumption details of reserved instances refreshed every hour?

Yes, the consumption details of reserved instances are refreshed every hour.

Can a reserved instance be applied to multiple pay-as-you-go instances at the same time?

What do I do if the billing method of an instance cannot be changed from subscription to pay-as-you-go?

You may be unable to change the billing method of an instance from subscription to pay-as-you-go due to one of the following reasons:

1. The instance is in a state that does not support the billing method change. For example, you have an unpaid order for the instance.

2. The instance is in the Expired state.

3. The billing method change is not allowed because instance information is changed. For example, the bandwidth of the instance is temporarily upgraded.

To resolve the preceding issue, perform the following operations:

• Check the status of the instance. Make sure that no unpaid order exists for the instance and the instance is not in the Expired state.

• Check the configurations of the instance. If you changed the configurations of the instance, undo the changes to restore the original configurations of the instance.

If the issue persists or an unknown error is reported after you perform the preceding operations, submit a ticket to obtain technical support from Alibaba Cloud.

Why am I prompted with an overdue payment when my subscription instances have not expired?

After you purchase subscription instances, if you use resources that are billed on a per-use basis, such as snapshots and pay-by-traffic public bandwidth, you are charged for the resources separately from the instances. When your account balance is insufficient to pay for the due pay-as-you-go charges, the payment becomes overdue. You can view your consumption details to check whether you have outstanding pay-as-you-go bills. For more information, see View billing details.

How is the billable time of a pay-as-you-go instance calculated? For example, if I created a pay-as-you-go instance at 01:30:00 and released it at 02:00:00, was the instance billed for a 30-minute or 1-hour period?

Pay-as-you-go instances are billed in 1-second increments. Payments are made every hour on the hour. The billable time of pay-as-you-go instances is automatically calculated. For example, if you created a pay-as-you-go instance at 01:30:00 and released it at 02:00:00, the billing cycle is from 01:00:00 to 02:00:00. The billable time of 1,800 seconds is calculated by using the following formula: 30 minutes × 60 = 1,800 seconds.

After I stop a pay-as-you-go instance or the instance is automatically stopped due to an overdue payment, am I still charged for the instance?

• Instance stop due to an overdue payment: When your account has overdue payments, your pay-as-you-go instances automatically stop and billing for the instances also stops. Instances do not always remain in the Stopped state after they are stopped due to overdue payments. For more information, see Pay-as-you-go.

• Manual instance stop: You can stop a running pay-as-you-go instance in the ECS console or by calling the StopInstance operation. When the instance is stopped, it enters the Stopped state. A stopped pay-as-you-go instance is billed based on the network type and whether economical mode is enabled for the instance.

  • Virtual Private Cloud (VPC):

    • If economical mode is enabled, a pay-as-you-go instance starts to be billed when the instance is created, and billing for specific instance resources stops when the instance enters the Stopped state and resumes when the instance is restarted. When a pay-as-you-go instance is stopped in economical mode, billing for the computing resources (vCPUs and memory) and static public IP address of the instance stops and billing for other resources, such as the disks and the elastic IP address (EIP), continues. For more information, see Economical mode.

    • If economical mode is disabled, billing for pay-as-you-go instances continues even if they are in the Stopped state.

  • Classic network: Pay-as-you-go instances in the classic network are billed regardless of whether they are in the Stopped state.

Billing for pay-as-you-go instances stops after the instances automatically stop due to overdue payments. When pay-as-you-go instances are manually stopped, billing for the instances stops or continues based on the configurations and network type of the instances.

What do I do if an order cannot be placed to change the billing method of an instance from pay-as-you-go to subscription?

When I change the billing method of an instance from pay-as-you-go to subscription, does the billing method for network usage (also known as metering method) of the instance also change?

No, the billing method for network usage of the instance does not change. Only the billing method of instances and disks can be changed from pay-as-you-go to subscription. For information about how to change the billing method for network usage, see Overview of instance configuration changes.

I have an unpaid order to change the billing method of an instance from pay-as-you-go to subscription. If I upgrade the configurations of the instance, does the order remain valid?

An order is created when you change the billing method of your instance from pay-as-you-go to subscription. You must complete the payment to allow the change to take effect. If you upgrade the configurations of the instance before you complete the payment, the payment cannot be processed because the instance components are different and the original order no longer matches the instance components.

If you still want to change the billing method of the instance, cancel the unpaid order on the Orders page and then place a new order to change the billing method of the instance from pay-as-you-go to subscription.

Why am I unable to change a pay-as-you-go instance into a subscription instance?

What ECS instances support the economical mode?

For more information, see Economical mode.

Can I retain the computing and network resources of a stopped pay-as-you-go instance after I enable the default economical mode?

After you enable the default economical mode, you can specify whether to trigger the economical mode for a pay-as-you-go instance when you stop the instance. If the economical mode is not triggered for a pay-as-you-go instance when the instance is stopped, the computing and network resources of the instance are not released.

If you need to stop and then restart a pay-as-you-go instance within a short period of time, we recommend that you perform one of the following operations to prevent the economical mode from being triggered: Call the StopInstance operation with StoppedMode set to KeepCharging, or set Stop Mode to Standard Mode when you stop the instance in the ECS console.

Can the economical mode be triggered for ECS instances that are stopped from within their operating systems?

Can the economical mode be triggered for instances that are equipped with local storage?

No, the economical mode cannot be triggered for instances that are equipped with local storage.

When I attempt to restart an instance immediately after it is stopped in economical mode, an OperationConflict error is reported. Why?

When the economical mode is triggered for an instance, the computing resources (CPUs and memory) and static public IP address of the instance are recycled.

If you need to stop and then restart a pay-as-you-go instance within a short period of time, we recommend that you perform one of the following operations to prevent economical mode from being triggered: Call the StopInstance operation with StoppedMode set to KeepCharging, or set Stop Mode to Standard Mode when you stop the instance from the ECS console.

When I call the StartInstance operation to restart an instance that is stopped in economical mode, an OperationDenied.NoStock error is reported. Why?

When an instance is stopped in economical mode, the computing resources of the instance are recycled. If available resources are insufficient, an OperationDenied.NoStock error is reported when you attempt to restart the instance. We recommend that you try again later.

When I restart an instance that is stopped in economical mode, the public IP address of the instance changes. How do I prevent the IP address from changing?

When an instance is stopped in economical mode, its static public IP address is recycled. When the instance is restarted, it is automatically assigned a new static public IP address.

Can I release ECS instances on my own?

Yes, you can manually release or schedule the automatic release of pay-as-you-go instances. However, you cannot release subscription instances on your own.

If you have further questions, submit a ticket.

Why is a pay-as-you-go bill generated for my instance? What are the charges on the bill?

Why am I unable to change the billing method of an instance from subscription to pay-as-you-go?

Your ECS usage determines whether the billing method of your subscription instances can be changed to pay-as-you-go. Before you change the billing method of a subscription instance, make sure that the instance is in the Running or Stopped state.

How are ESSDs billed?

After you create an Enterprise SSD (ESSD), you are charged for the disk capacity regardless of whether the ESSD is attached to an ECS instance. ESSDs support the subscription and pay-as-you-go billing methods.

• Subscription: Cloud disk capacity (GiB) × Unit price × Subscription duration.

• Pay-as-you-go: Cloud disk capacity (GiB) × Unit price × Usage duration.

For more information about the billing rules of ESSDs at performance levels 0, 1, 2, and 3 (PL0, PL1, PL2, and PL3 ESSDs), see Block storage devices. The prices of PL0, PL1, PL2, and PL3 ESSDs vary based on the region. For information about the prices, visit the Pricing tab of the Elastic Compute Service product page.

How do I purchase a standard SSD and how much is the price of a standard SSD?

For information about the instance families that support standard SSDs, see Overview of instance families. The prices of standard SSDs vary based on the region. For information about the prices, visit the Pricing tab of the Elastic Compute Service product page.

How is a separately purchased pay-as-you-go data disk billed?

After you create a pay-as-you-go data disk, you are charged for the disk capacity regardless of whether the disk is attached to an ECS instance.

Pay-as-you-go: Cloud disk capacity (GiB) × Unit price × Usage duration.

For more information about the billing rules, see Block storage devices. The prices of cloud disks vary based on the region. For information about the prices, visit the Pricing tab of the Elastic Compute Service product page.

What is an SCU?

SCUs are subscription storage resource plans that can be used to offset the pay-as-you-go bills of storage resources, such as cloud disks. Compared with cloud disks purchased together with subscription ECS instances, SCUs used together with pay-as-you-go cloud disks offer a better combination of cost-effectiveness and flexibility. For more information, see Overview.

Which storage resources can use SCUs?

Can an SCU be used alone?

No, SCUs cannot be used alone. SCUs must be matched to and used with pay-as-you-go cloud disks or snapshots to offset bills.

What rules apply when you use SCUs?

SCUs offset the pay-as-you-go bills of cloud disks or snapshots based on a variety of deduction factors. For more information, see the Offset rules section of the "SCUs" topic.

How are SCUs billed?

SCUs are billed based on their capacity. SCU capacity prices vary based on the region. For information about SCU capacity prices in each region, visit the Pricing tab of the Storage Capacity Unit product page.

How do I view the Internet traffic bills of an ECS instance?

How is the inbound and outbound traffic of pay-as-you-go instances billed?

Traffic between ECS instances or between ECS instances and other Alibaba Cloud services in the same VPC is free of charge. Traffic between ECS instances and the Internet is billed based on the following rules:

• Inbound Internet traffic is free of charge. Inbound Internet traffic refers to traffic from the Internet to ECS instances, such as traffic generated when you download resources from the Internet to your ECS instances or when your users upload resources to your ECS instances by using an FTP client.

• Outbound Internet traffic is billed. Outbound Internet traffic refers to traffic from ECS instances to the Internet, such as traffic generated when your ECS instances provide external access or when your users download internal resources from your ECS instances by using an FTP client.

For more information about bandwidth billing, see Public bandwidth.

What is the difference between the pay-by-bandwidth and pay-by-traffic billing methods for network usage?

If you select pay-by-bandwidth as the billing method for network usage, you are charged based on the specified public bandwidth. Your actual outbound public bandwidth is capped at the specified bandwidth.

If you select pay-by-traffic as the billing method for network usage, you are charged based on actual data transfers. To prevent out-of-control fees caused by traffic bursts, you can specify a bandwidth limit for outbound Internet traffic.

For more information, see Public bandwidth.

An instance has a static public IP address that uses the pay-by-bandwidth metering method. Why is the price different after I change the metering method of the static public IP address to pay-by-traffic, convert the static public IP address into an EIP, and then change the billing method of the EIP to subscription?

After you change the metering method of the static public IP address that is assigned to an instance from pay-by-bandwidth to pay-by-traffic, the static public IP address uses the pay-as-you-go billing method. If you convert the static public IP address into an EIP by performing the operations described in Convert the static public IP address of an ECS instance to an EIP and then change the billing method of the EIP from pay-as-you-go to subscription by performing the operations described in Switch metering methods, the payable amount for changing the billing method of the EIP is different from the refundable amount for changing the metering method of the static public IP address. This is because you purchased the instance at a discounted rate and do not receive any discount when you change the billing method of the EIP from pay-as-you-go to subscription.

Will the EIP associated with an ECS instance be refunded when the instance is refunded?

No, you are still charged for the EIP even after the EIP is disassociated from the ECS instance. If you no longer require the EIP, release the EIP. After the EIP is released, you are no longer charged. For more information, see Release a pay-as-you-go EIP.

Can I adjust the maximum bandwidth that I specified?

Yes, after you create an instance, you can adjust the maximum bandwidth that you specified for the instance. For more information, see Overview of instance configuration changes.

Will I be charged for the traffic generated for ECS instances under attack?

You will not be charged for the inbound traffic from the Internet to ECS instances under attack, but will be charged for the outbound traffic from the instances to the Internet.

We recommend that you use Security Center to reinforce the security of ECS instances.

Can I select the pay-by-traffic billing method for network usage when I purchase a subscription instance?

Yes, you can select the pay-by-traffic billing method for network usage when you purchase a subscription instance. For more information, see Create an instance on the Custom Launch tab.

For more information about the pay-by-traffic billing method, visit the Pricing tab of the Elastic Compute Service product page.

How am I charged when I select the pay-by-traffic billing method for network usage?

Pay-by-traffic is a pay-as-you-go billing method in which you are charged based on the actual amount of data transferred. Payments are completed every hour on the hour. To ensure that services run as expected, make sure that your account balance is sufficient. To prevent out-of-control fees caused by traffic bursts, you can specify a bandwidth limit for traffic.

Can I change the billing method for network usage of a subscription instance from pay-by-bandwidth to pay-by-traffic?

Yes, you can change the billing method for network usage of a subscription instance from pay-by-bandwidth to pay-by-traffic by using the bandwidth downgrade feature. However, you can make the change only a limited number of times. For more information, see Modify the public bandwidth configurations of an instance associated with an auto-assigned public IP address.

You can also use the renewal and configuration downgrade feature to change the billing method for network usage. The new configurations do not take effect until the next billing cycle starts. For more information, see Renewal and configuration downgrade.

Can I adjust the maximum bandwidth for an ECS instance at any time?

Yes, you can use the bandwidth downgrade feature to adjust the maximum bandwidth for an ECS instance at any time. When you set the maximum bandwidth to a smaller value, the new value takes effect immediately. A maximum of three refunds can be made for each instance. Exercise caution when you downgrade the configurations of an instance.

If you downgraded the configurations of a subscription instance when you renewed it, you cannot upgrade or downgrade the instance configurations again until the new billing cycle starts.

If the pay-by-traffic billing method for network usage is used for a subscription instance, can the instance continue to use the public bandwidth service when a payment becomes overdue?

Overdue payments do not affect the running of subscription instances, but do cause the pay-by-traffic public bandwidth service to be suspended. After the public bandwidth service is suspended, the instances lose Internet connectivity. You can continue to use the public bandwidth service only after you complete the overdue payments. To ensure that services run as expected, make sure that your account balance is sufficient.

If the pay-by-traffic billing method for network usage is used for a subscription instance, will I be notified when a payment becomes overdue in my account?

Yes, you will be notified by text message. To ensure that services run as expected, make sure that your account balance is sufficient.

If the pay-by-traffic billing method for network usage is used for a subscription instance, can I upgrade the instance type after a payment becomes overdue in my account?

No, you can upgrade the instance type only after you complete the overdue payment.

If the pay-by-traffic billing method for network usage is used for a subscription instance, does the public bandwidth service of the instance automatically resume after I settle overdue payments?

If the public bandwidth service was suspended due to an overdue payment, the service automatically resumes when the overdue payment is completed.

How am I billed for network usage after I change the billing method for network usage of a subscription instance from pay-by-bandwidth to pay-by-traffic?

When you change the billing method for network usage of a subscription instance from pay-by-bandwidth to pay-by-traffic, you are billed for network usage based on actual data transfers. Payments are settled every hour on the hour. For information about the prices, visit the of the Elastic Compute Service product page.