Overview

In early 2024 Amazon upgraded the Finances API version 0 by inserting a new attribute named TransactionNumber into the AdjustmentItem payload. This identifier connects financial adjustments directly to the originating transaction—such as an Amazon Shipping invoice—making it easier for sellers to reconcile accounts, generate accurate reports, and resolve disputes.

Key Points

• New attribute introduced — AdjustmentItem objects now return a string field called TransactionNumber that mirrors the identifier used in the source transaction.
• Invoice correlation enabled — Sellers using Amazon Shipping can align the TransactionNumber with the invoice number displayed in the Shipping console, establishing a one‑to‑one relationship between finance entries and shipping costs.
• No version migration required — The enhancement is delivered inside the existing v0 endpoint, so current integrations continue to function without switching to a newer API version.
• Field appears conditionally — TransactionNumber is populated only when the adjustment originates from a service that generates a transaction number; otherwise the field is null or omitted.
• Backward‑compatible response — All previously available fields (AdjustmentAmount, ReasonCode, etc.) remain unchanged, preserving existing parsing logic while adding the new identifier.

How the TransactionNumber Addition Works

1. Request format stays the same — Sellers keep calling GET /finances/v0/transactions with the same query parameters (e.g., MarketplaceId, CreatedAfter, CreatedBefore). For instance, a seller pulling adjustments for the last 30 days still sends the identical URL string as before.
2. Response payload expands — Each AdjustmentItem now includes a TransactionNumber key. If a seller retrieved adjustments for July 2024, a sample JSON entry might read "TransactionNumber": "AMZSH-INV-20240715-00123" alongside the adjustment amount and reason.
3. Population is selective — The new field is filled only when the underlying service supplies a transaction identifier. An adjustment tied to a generic Amazon rebate would return , signaling that no direct transaction link exists.