Written and maintained by CASRAI Editorial Board
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Short answer: a lot code is the alphanumeric identifier a manufacturer or packer gives one production group of a product so every unit in that group can be traced together. Federal rules use the idea for device, drug and food labels. This is general reference information, not medical advice.
Definition and scope
“Lot code” is an everyday term, not one defined term in the regulations. The regulations define the pieces. For devices, 21 CFR 801.3 defines a lot or batch as one or more finished devices of a single type, model, class, size, composition or software version, manufactured under essentially the same conditions and intended to have uniform characteristics and quality within specified limits. For food, 21 CFR 1.1310 defines a traceability lot code as a descriptor, often alphanumeric, used to uniquely identify a traceability lot within the records of the traceability lot code source.
The code identifies a group, not a single unit. A serial number identifies one unit, and the regulation lists the two as separate items. For the basics of numbering, see the guide to the lot number; for locating the code on packaging, see how to read a lot number.
How a lot code is used in practice
The lot code is the link between a physical package and the manufacturer’s records. Under 21 CFR 201.18, the lot number on a drug label “should be capable of yielding the complete manufacturing history of the package.” That is why a code printed on a box can be matched to a recall notice or to a return authorization: the holder of the records can tell which production group the box belongs to. For how returns are processed once a code is identified, see the guide to RMA meaning.
The regulations do not set one universal format for the characters. Each manufacturer or packer uses its own scheme, so the code should be recorded exactly as printed rather than interpreted.
Lot code across device, drug and food labels
The same everyday phrase maps to three separate federal provisions. Each row below is taken from the cited section of the Code of Federal Regulations.
| Product type | Term in the rule | What the rule says | Source |
|---|---|---|---|
| Medical device | Lot or batch; production identifier | Defines lot or batch (801.3). The production identifier is a conditional, variable part of the Unique Device Identifier (UDI) that identifies, when on the label, the lot or batch, serial number, expiration date, manufacture date, or an HCT/P distinct identification code. Under 801.40(b), when a device label includes a lot or batch number, serial number, manufacturing date or expiration date, the UDI must include a production identifier segment that conveys that information. | 21 CFR 801.3, 801.40 |
| Drug | Lot number (control number) | The lot number on a drug label should be capable of yielding the complete manufacturing history of the package; an incorrect lot number may be regarded as causing the article to be misbranded. | 21 CFR 201.18 |
| Food on the Food Traceability List | Traceability lot code | A descriptor, often alphanumeric, that uniquely identifies a traceability lot within the records of the code’s source, the place where the food was assigned the code. | 21 CFR 1.1310 |
For the device row, see the guides on UDI labels and medical device tracking requirements. For drugs, see pharmaceutical serialization.
Food traceability timeline
FDA’s food traceability rule says a traceability lot code is assigned when a Food Traceability List food is initially packed (a raw agricultural commodity other than from a fishing vessel), first received on land (food from a fishing vessel), or transformed; shippers must not create a new code. The original compliance date was January 20, 2026. As of 2026-11-03, FDA’s page describes a proposed extension to July 20, 2028 and a congressional direction that FDA not enforce the requirements before then, while parts of the page’s text still show 2026.
Where it matters for labs, clinics and receiving
The checklist below is an editorial record-keeping aid. Each item is tied to a rule above; it is not a legal compliance procedure, and it does not replace the manufacturer’s instructions or your facility’s policies.
- Record the code exactly as printed. Rules define it as an identifier within the manufacturer’s or packer’s records (21 CFR 201.18, 1.1310), so a transcription error breaks the link to those records.
- Record the expiration or manufacture date printed with it, when present. For devices these are listed alongside the lot or batch as production identifier fields (21 CFR 801.3).
- Check whether the label carries a UDI and whether it is readable in plain text and by machine. Section 801.40 provides for both forms.
- Do not treat a serial number and a lot code as the same field. The regulation lists them separately, so keep them in separate fields.
- Keep the code with the supplier paperwork for the shipment. If a product needs to be returned or a recall notice arrives, the code is what is matched to the manufacturer’s records.
Common misunderstandings
- “A lot code is a serial number.” No. A lot or batch covers a group of devices made under essentially the same conditions; a serial number is a separate production identifier (21 CFR 801.3).
- “There is one standard format.” The rules cited here define what the code must do (identify a group, support traceability), not how many characters it has.
- “The lot code is the product’s barcode number.” The product identifier and the production identifier are different parts of a UDI; the lot or batch sits in the production identifier part. See the comparison of GTIN vs UPC for the product-number side.
- “A wrong lot number is only a typo.” For drugs, 21 CFR 201.18 says an incorrect lot number may be regarded as causing the article to be misbranded.
FAQ
What is a lot code?
It is the identifier assigned to one production group of a product, used to trace every unit in that group to the manufacturer’s or packer’s records.
Is a lot code the same as a lot number or batch number?
In everyday use they are used interchangeably. In the device rule, “lot or batch” is the defined term (21 CFR 801.3); the drug rule says “lot number” (21 CFR 201.18); the food rule says “traceability lot code” (21 CFR 1.1310).
Is a lot code the same as a serial number?
No. The device regulation lists lot or batch and serial number as separate production identifiers.
Why does the lot code matter for a return or recall?
Because it ties the package to the production records, so the group affected can be identified. See RMA meaning for return handling.
Sources
- 21 CFR 801.3, Definitions (lot or batch; production identifier), eCFR, checked 2026-11-03.
- 21 CFR 801.40, Form of a unique device identifier, eCFR, checked 2026-11-03.
- 21 CFR 201.18, Drugs; significance of control numbers, eCFR, checked 2026-11-03.
- 21 CFR 1.1310, Definitions for traceability records, Cornell LII, checked 2026-11-03.
- FDA, FSMA final rule on requirements for additional traceability records for certain foods, checked 2026-11-03.
