---
title: Book transfers
slug: concepts/payments/book-transfers
description: A Cross River book transfer moves funds between accounts. Both debit and credit must succeed. Returns a Transaction ID (GUID) and 17-char Trace number (starting with T).
docTags: 
createdAt: 2025-09-14T06:49:06.848Z
---

:::CtaButton{label="Book transfer APIs" docId="B8Djj8OY_SyerGPU3D1vU" openInNewTab="true"}

:::

## Cross River book transfers solution

A book transfer in Cross River involves a debit of one account and a credit of another account in Cross River, completed as a one action. A book transfer moves funds between accounts, while also populating a description that includes the *from* and *to* accounts. 

For the transfer to be considered completed, both sides must be executed.

For example, the debit account has insufficient funds, and the credit operation will not be complete. This mechanism ensures accounts are never out of balance and makes following the movement of funds much easier. 

Transfers have two unique identifiers returned in response to the request:

- Transaction ID, which is in the form of a GUID
- Trace number, which has 17 characters and begins with the letter 'T'

[Learn more about payment transactions and settlement](docId\:luDEbxnwU8p7Knb_bDM6I) 

## Cross River transactions

**Post Transaction** allows you to select a specific transaction code and enter a unique transaction description.

## Tutorials

See our COS Explorer tutorial to learn how to:

[Perform a book transfer](docId\:B_wgTa_Ok59znDQ_b3g3-)