FBA shipment ID format checker.

Three IDs that all get called "shipment ID"

Amazon’s older inbound API (v0) returns a ShipmentId for each shipment, “originally returned by the createInboundShipmentPlan operation”. Its example values are FBA15DJ9S3J5 and FBA15DF2763D. The archived MWS label guide treats the same FBA shipment identifier as the value on the shipping label.

The 2024-03-20 inbound API separates the idea. It has a shipmentConfirmationId, defined as “the confirmed shipment ID which shows up on labels (for example, FBA1234ABCD)”, and a different shipmentId, defined as an “identifier of a shipment”, constrained to exactly 38 characters from letters, digits and hyphens (examples begin sh). Plans have an inboundPlanId with the same 38-character constraint (examples begin wf). So if you copy an ID out of an API response and it is 38 characters long, it is not the one printed on labels.

Amazon’s examples show the label ID as FBA followed by 8 or 9 letters and digits (FBA15DJ9S3J5, FBA15DF2763D, FBA1234ABCD), and the archived MWS label guide uses FBA1MMD8D0, with 7. Amazon gives no length rule, so the tool accepts 6 to 10 characters after FBA and labels the result “observed”. The prefix letters and digits are not decoded because Amazon does not explain them.

How the check works, variable by variable

The checker removes spaces and capitalises letters, then tests in this order. First it asks whether the value is a box ID, meaning a shipment ID plus U plus exactly six digits; if so it says so and shows the shipment part. Second, whether it is FBA plus 6 to 10 letters or digits; if so it passes. Third, whether it is 38 characters of letters, digits and hyphens, the shape of the 2024 API’s shipmentId and inboundPlanId; if so it explains that this is an internal API identifier. Otherwise it explains what is wrong.

Case matters little here. The tool upper-cases FBA IDs for you, but a 38-character API ID is shown as pasted because the API constraint allows lower-case letters.

Worked example (Amazon’s documentation values)

FBA15DJ9S3J5 is FBA plus nine characters, so it passes as a label-style shipment ID. FBA15DJ9S3J5U000002 is that shipment’s second box and is identified as a box ID. sh1234abcd-1234-abcd-5678-1234abcd5678 is 38 characters with hyphens, the documented placeholder for an API shipmentId, and is identified as an API ID rather than a label ID. FBA15 alone fails because it has only two characters after FBA.

These are documentation values, not real shipments.

What the shipment statuses mean

Amazon’s v0 inbound model defines each status. These are its descriptions, lightly shortened:

The 2024 API states a typical path: a shipment usually starts as UNCONFIRMED, moves to WORKING after a placement option is confirmed, and reaches READY_TO_SHIP once labels are generated. Its full list also includes ABANDONED, MIXED and RECEIVING among others, but Amazon’s model gives meanings only for the path above.

Shipment ID, box ID and tracking ID

One shipment contains many boxes. Each box gets a box ID built from the shipment ID, which the FBA box ID guide explains. Carriers add their own tracking numbers on top for small-parcel shipments. If a receiving discrepancy appears later, you match it by shipment ID, so keep the exact label ID with your packing records. The inbound discrepancy reconciler compares expected and received units from a report.

Common mistakes

The shipment name is not the shipment ID. Amazon’s v0 model has a separate ShipmentName field, “the name for the inbound shipment”, which you can set yourself and which often looks nothing like an FBA ID. Other slips are pasting a carrier tracking number, using a box ID where a shipment ID is wanted, and mixing the 38-character API shipmentId with the label ID when reconciling a report against a label. If two systems disagree on an ID, check its length first: 38 characters means an API identifier, an FBA prefix means the label ID.

Who this is for

FBA sellers and prep centers copying IDs between Seller Central, spreadsheets and carrier portals, developers moving from the v0 API to the 2024 API and wondering which ID goes where, and support staff checking which of three similar IDs a customer pasted.

What this does not cover

• It does not look a shipment up, confirm it exists or show its status.
• It does not state a length rule for FBA IDs, because Amazon has not published one.
• It does not read Seller Central pages that need a login, so it does not describe screens we could not see.
• It does not store, send or log what you type.