---
title: "Create a book transfer"
method: POST
path: "/v2/transfers/book"
---

# Create a book transfer

`POST /v2/transfers/book`

## Request

- Base URL: `https://api.slash.com`
- URL: `https://api.slash.com/v2/transfers/book`
- Auth: API key in header `X-API-Key`

Move USD between virtual accounts in the same Account.

## Headers

- `X-Idempotency-Key` string, required

## Request body

- TransferCreateBook: Move USD between virtual accounts in the same Account.
  - `amount` UsdMoney, required: A positive USD amount expressed in cents.
    - `amount` integer, required: Amount in cents. For example, `1250` represents USD 12.50.
    - `currency` 'USD', required
  - `fromAccount` string, required: Source virtual-account id with the `subaccount_` prefix.
  - `toAccount` string, required: Destination virtual-account id in the same Account.
  - `description` string: Human-readable private transfer memo.

## Response `200`

The created book transfer.

- TransferBook: A transfer between Slash balances in the same Account.
  - `id` string, required: Transfer id with the `transfer_intent_` prefix.
  - `accountId` string, required: Account containing the source balance.
  - `fromAccount` string: Source virtual-account id, when the transfer is scoped to one.
  - `amount` Money, required: A signed monetary amount expressed in minor units.
    - `amount` integer, required: Amount in the currency's minor units.
    - `currency` string, required: Uppercase ISO 4217 currency code.
  - `description` string: Human-readable private transfer memo.
  - `statementDescriptor` string: Statement or network descriptor supplied when the transfer was created.
  - `billId` string: Bill this transfer pays, when it was linked to one, with the `bill_` prefix. Set from `billId` at creation or by `POST /v2/bills/{billId}/payments`. Absent when your key can't see that bill.
  - `transactionIds` string[], required: Transaction ids produced by this transfer.
  - `createdAt` string, date-time, required: Time the transfer was created.
  - `submittedAt` string, date-time: Time the transfer was submitted for processing.
  - `settledAt` string, date-time: Time the transfer settled.
  - `failedAt` string, date-time: Time the transfer failed.
  - `canceledAt` string, date-time: Time the transfer was canceled.
  - `type` 'book', required
  - `status` 'pending' | 'scheduled' | 'in_review' | 'canceled' | 'failed' | 'settled', required: Lifecycle state of a book transfer between Slash balances.
  - `toAccount` string: Destination virtual-account id.

## Other responses

- `400`: - `global_usd_account_not_supported` — The account is a Global USD account, which this request does not support. - `to_account_in_other_account` — A book transfer moves money between virtual accounts of one account, but `toAccount` belongs to a different account than `fromAccount`. - `to_account_same_as_from_account` — A book transfer moves money between two virtual accounts, but `toAccount` is the same one as `fromAccount`. - `invalid_request (request shape)` — The body, query, or headers failed validation, or a required header is missing. `details` has one entry per failing location, keyed by JSON pointer or header name.
- `401`: - `unauthorized` — API key authentication is missing or invalid.
- `403`: - `forbidden` — The credential is not permitted to perform this action on the resource. When the resource is a field of the request, `details` names that `field` and the `id` it received. - `ip_allowlist_required` — The legal entity does not enforce an IP allowlist. Creating or cancelling transfers requires one, and the request must come from an allowlisted IP. - `forbidden (legal entity)` — The credential is not permitted to act for the selected legal entity. - `not_available` — Public API v2 is not yet available. Use [Public API v1](https://docs.slash.com/introduction) in the meantime. - `user_api_key_required` — The API key is scoped to a legal entity rather than a user. Every v2 request needs a user API key, created under Settings → API keys in the Slash dashboard, together with the `x-legal-entity` header.
- `404`: - `not_found` — No resource matches the identifier. When the identifier is a field of the request, `details` names that `field` and the `id` it received.
- `409`: - `insufficient_funds` — The source account does not hold enough to cover this transfer. Nothing was moved; fund the account or lower the amount and retry. - `conflict (idempotency key reused)` — A consumed `X-Idempotency-Key` was reused; the original response is not replayed.
- `429`: The request exceeded the applicable rate limit. The response body is plain text, not the error object; clients must not depend on its wording.
- `500`: - `internal` — Slash could not complete the request. Quote `referenceId` when contacting Slash support.

## Changes

- **2026-10-16** `8b5d371ffeea`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/slashfi/apis/slash-public-api/changes/v2/transfers/book/post.md)

---

[API](https://skmtc.dev/slashfi/apis/slash-public-api.md) - [All operations](https://skmtc.dev/slashfi/apis/slash-public-api/llms.txt) - [OpenAPI document](https://skmtc.dev/slashfi/apis/slash-public-api/revisions/eaed2d63c9e2?raw)