# Instance to instance transfer
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You can build your contact center within a single Amazon Connect instance. However, managing multiple lines of business in one instance complicates access control. Instance transfer lets you maintain the benefits of Amazon Connect while allowing individual business units to run and control their own contact centers.

Instance transfer enables you to centralize IVR functions in one instance. After customers select their options, you transfer calls to individual Amazon Connect instances. This allows independent management of each business unit while maintaining isolation of access controls but eliminates the cost of the telephony between the two systems.

## How it works
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Instance transfer uses our routing AI to identify the telephone number being called. If the number belongs to your Amazon Connect account, the call transfers across the AWS Backbone to the Amazon Connect instance that owns the number, removing the telephony transfer costs for both instances.

 **Instance transfers require:** 
+ Unlimited AI
+ Amazon Connect Telephony using DID, Toll-Free, Shared Cost numbers only
+ Direct ownership relationship within an AWS Organization (To enable AWS wide transfers, open a support case with AWS Support.)

 **Instance transfers are not supported:** 
+ Outside of an AWS Organization with no direct ownership relationship
+ A-La Carte (Classic) Instances

## Passing data between instances
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Instance transfer within the AWS network preserves contact attributes for transferred calls. To pass context between instances:

1. Set context attributes on the original call leg, capturing whatever data you wish to pass.

1. When the call reaches the next instance, the second instance should then retrieve the information about the original by using a Lambda call using [DescribeContact](https://docs.aws.amazon.com/connect/latest/APIReference/API_DescribeContact.html) API passing in the original contact ID. The contact ID is retrievable from the ` connect:CrossInstanceInfo` segment attributes. More information on how to determine the ID can be found [here](troubleshoot-instance-transfer.md#locate-instance-transfer-information).

## Service availability
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Instance transfer is available in all AWS regions where Amazon Connect is offered, except AWS GovCloud (US-West) and Africa (Cape Town).

## Transfers cost considerations
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Instance transfer of calls between instances within the same AWS Region is covered by the existing cost structure for Amazon Connect and Contact Centre Telecom, allowing you to run segmented or globally distributed follow the sun models without additional telephony transfer costs.