# Understanding data transfer charges
<a name="cur-data-transfers-charges"></a>

You can identify your AWS data transfer charges using the [lineItem/UsageType](Lineitem-columns.md#Lineitem-details-U-UsageType) column of your AWS CUR.

**Note**  
Data transfer charges can vary depending on the services used and the source AWS Region. For detailed pricing information, refer to the service’s pricing page. For example, see [Amazon EC2 On-Demand Pricing](https://aws.amazon.com/ec2/pricing/on-demand/) for detailed pricing information about Amazon EC2 data transfer.

## Data transfer within an AWS Region
<a name="data-transfer-within-region"></a>

Data transfer between Availability Zones in the same AWS Region have a **UsageType** of `Region-DataTransfer-Regional-Bytes`. For example, the `USE2-DataTransfer-Regional-Bytes` usage type identifies charges for data transfer between Availability Zones in the US East (Ohio) Region.

For a given resource, you’re charged for both inbound and outbound traffic in a data transfer within an AWS Region. This means for each resource metered, you'll see two `DataTransfer-Regional-Bytes` line items for each data transfer. Confirm the service's pricing page for more information, because some services have in-Region traffic at no cost.

## Data transfer between AWS Regions
<a name="data-transfer-between-regions"></a>

Data transfer between different AWS Regions can have the following usage types:
+ `Source Region-Destination Region-AWS-In-Bytes`: Measures incoming data transfer TO the destination Region FROM another specific AWS Region.
+ `Source Region-Destination Region-AWS-Out-Bytes`: Measures outgoing data transfer FROM the source Region TO another specific AWS Region.
+ `Source Region-AWS-In-Bytes`: This usage type appears when traffic flows via VPC Peering.
+ `Source Region-AWS-Out-Bytes`: This usage type appears when traffic flows via VPC Peering.

For each resource, data transfer between AWS Regions corresponds to two line items in your report:
+ A line item for the data transferred into the destination Region 
+ A line item for the data transferred out from the source Region

There's no charge for the data transferred into the destination Region. The data transfer charge is determined by the data transferred out from the source Region.

For example, a data transfer from the `USE2` Region to the `APS3` Region will have both a `APS3-USE2-AWS-In-Bytes` line item and a `USE2-APS3-AWS-Out-Bytes` line item. The `APS3-USE2-AWS-In-Bytes` line item has no corresponding charge. The data transfer charge is associated with the `USE2-APS3-AWS-Out-Bytes` line item.

## Data transfer out to the internet
<a name="data-transfer-out-internet"></a>

Data transfer from AWS to the internet have a **UsageType** of `Region-DataTransfer-Out-Bytes`. For example, the `USE2-DataTransfer-Out-Bytes` usage type identifies charges for data transfer from the `USE2` Region to the internet.

There’s no charge for data transfer from the internet to AWS.

**Note**  
Data transfer usage types that don’t have the Region prefix, such as `DataTransfer-Regional-Bytes` or `DataTransfer-Out-Bytes`, represent data transfer from the US East (N. Virginia) Region.

## Direct Connect traffic
<a name="direct-connect-traffic"></a>

Direct Connect data transfer over a public virtual interface have usage types that end with `DataXfer-In` or `DataXfer-Out`.

Direct Connect data transfer over a private or transit virtual interface have usage types that end with `DataXfer-In:dc.3` or `DataXfer-Out:dc.3`.

## S3 Transfer Acceleration traffic
<a name="s3-transfer-acceleration-traffic"></a>

Amazon S3 data transfer using S3 Transfer Acceleration have usage types that contain `ABytes`:
+ Between Amazon S3 and Amazon EC2: Usage types that end with `C3DataTransfer-In-ABytes` or `C3DataTransfer-Out-ABytes`
+ Between Amazon S3 and the internet: Usage types that end with `DataTransfer-In-ABytes` or `DataTransfer-Out-ABytes`
+ Between Amazon S3 and CloudFront: Usage types that end with `CloudFront-In-ABytes` or `CloudFront-Out-ABytes`
+ Between Amazon S3 buckets in different AWS Regions: Usage type of `Source Region-Destination Region-AWS-Out-ABytes`

## CloudFront traffic
<a name="cloudfront-traffic"></a>

CloudFront data transfer have a usage type of `Region-DataTransfer-Out-Bytes` or `Region-DataTransfer-Out-OBytes` coupled with the product code `AmazonCloudFront`. The Region prefix in the usage type refers to the CloudFront Edge location used in the data transfer. For example, the `AP-DataTransfer-Out-Bytes` usage type identifies charges for data transfer from the AP Region to the internet.

**Tip**  
Use the [lineItem/ProductCode](Lineitem-columns.md#Lineitem-details-P-ProductCode) column to distinguish CloudFront data transfer from data transfer out to the internet. The usage types for these data transfer types look similar.