Traceability lot codes: who assigns them, when, and how to keep them clean

The traceability lot code (TLC) is the thread that ties every record in the FDA Food Traceability Rule together. Every business that handles a lot records the same code, so FDA can follow that lot from one business to the next.

The rule is specific about who assigns the code and when. It says almost nothing about what the code looks like. This guide covers both, and flags what is a rule and what is only an idea. FDA’s own traceability lot code page is worth a read alongside it.

What the rule requires

A TLC is a descriptor, often alphanumeric, that uniquely identifies a traceability lot within the records of the traceability lot code source, the place that assigned it. A traceability lot is a batch or lot of food that has been initially packed, received by the first land-based receiver, or transformed.

You must assign a TLC when you do any of these (21 CFR 1.1320):

Initially pack a raw agricultural commodity, other than a food obtained from a fishing vessel.
Perform the first land-based receiving of a food obtained from a fishing vessel.
Transform a food into a listed food, for example by mixing, cutting, repacking or relabeling.

For any other activity, such as shipping, you must not create a new code. The code you received is the code you keep and pass on.

One exception: if you receive a listed food from a business the rule does not cover, such as an exempt small farm, you assign a code if none exists. Retail food establishments and restaurants are excepted.

FDA’s FAQ adds a nuance for repacking. Repacking is a transformation and usually gets a new TLC. If you repack within the same lot without mixing lots, you may keep the original code. Your location becomes the new TLC source.

The TLC source goes with the code

The TLC source is the place where the food was assigned its code. Shipping and receiving records that carry the code also carry either the location description for that place (business name, phone number, address or coordinates, city, state, zip) or a TLC source reference. FDA’s examples of a reference are an FDA food facility registration number or a web address that gives FDA the location description.

The source is always a place where the food was physically handled. Corporate headquarters may decide the codes, but that does not make headquarters the source. FDA’s FAQ does allow a headquarters to serve as the TLC source reference, if it can give FDA the source’s location description quickly and at no cost.

The code must also be linked to the other data for the lot. One common way is to print it on the invoice or bill of lading. See key data elements by event for the full lists.

Example code formats

The rule does not prescribe a format. Your traceability plan must describe how you assign codes, such as “Julian date plus product code.” Here are examples. None is required.

Julian date, product, run: 26275-HRB-02. Herbs, second run, day 275 of 2026.
Calendar date, line, batch: 20261002-L1-B03.
Sequence number per site: PKR-000412.
Product ID plus lot: a GS1 barcode that carries the product’s GTIN and a lot number, if your buyers use GS1 labels.

Whatever you pick, it has to be unique among your own lots. FDA also notes that the rule does not tell you how big a lot should be, and that smaller lots can mean less food is affected in a recall.

Where to put the code

The rule does not require the TLC on the product label or package. It can reach the next business on a bill of lading, an advance ship notice, an email, or a QR code on the package or a related document. The receiver just has to get it in a form that lets them keep their records. Some ideas:

Case label, in human-readable text and a barcode or QR code
A “lot” column on the invoice and bill of lading, next to the product line
The TLC source name and address, or a reference, printed once per document
A QR code that opens a page with the TLC source details

Some retail buyers already require lot codes on cases. Check your supplier agreements.

When a supplier does not send a code

If your supplier is covered by the rule, it must give you the TLC and the other shipping data. If it did not:

Check the case label, invoice, bill of lading and advance ship notice. The code is often on one of them.
Ask the supplier in writing, and keep the reply.
Record what you did receive and note what is missing, so you can show the gap.
Put the requirement in your supplier terms or purchase orders.

FDA’s February 2026 draft guidance, which is not binding, says there is no safe harbor. You stay responsible for your own receiving records, so talk to your supplier.

Do not invent a code and pass it on as the supplier’s TLC. You may keep your own internal lot code for inventory, and you may send it as an extra. The TLC you send must be the one assigned by the TLC source.

If the supplier is not covered by the rule, you assign a code at receiving, as above, unless you are a retailer or restaurant.

Common mistakes

Reusing a code across days or lines. If two different lots share a code, a recall may reach more product than needed. The code has to be unique within your records.
Changing the code after shipping. A distributor should not replace the code it was given with its own. Only transformation creates a new one.
Leaving the code off paperwork. A code on the case but not the invoice breaks the link to the other data.
Missing TLC source. The code is incomplete without the place it came from.
Writing codes down later. Capture them at receiving and packing, when the label is in front of you.

Quick steps

Decide which of your activities trigger a code: initial packing, first receiving from a vessel, or transformation.
Choose a format and a lot size, and write both into your traceability plan.
Print the code and the TLC source on case labels or documents.
Record supplier codes at receiving, every time.
Run a mock trace of one lot every quarter. The 24-hour spreadsheet guide shows how.

FDA published a discussion paper in 2026 on possible flexibilities for lot-level tracking, including for distributors that ship mixed-lot pallets. It is for discussion only and is not guidance. Follow the rule as written and watch FDA’s Food Traceability Rule page for updates.

Where Lotcrumb fits

Lotcrumb is being built to generate lot codes in your chosen format, link them to the records you already keep, and carry supplier codes through to your own shipments. Join the waitlist for early access.

This guide is general information, not regulatory advice. Confirm your obligations with FDA guidance or a food safety professional.