semiatic
SN

Serial number (SN)

The standard’s wording, as the sources below reproduce it:

“Indicates the manufacturer’s serial number so that a specific medical device can be identified.”

ISO 15223-1:2021, 5.1.7 · ISO 7000-2498

What it means for you

Unlike LOT, a serial number belongs to one single device. It appears on equipment you keep — meters, pumps, hearing aids, implants — and is what the maker needs for a warranty, repair or a recall that affects individual units.

Whether a device is right for you is a question for your pharmacist, nurse or doctor.

What it looks like
The letters SN inside a rectangle, followed by a number unique to that one unit.
Where you see it
Rating plates and battery compartments of blood-glucose meters, blood-pressure monitors and other electrical devices; implant cards; the box of reusable equipment.
Other names
serial no.; S/N; SN

What it does not tell you

It does not say when or where the unit was made, and it is not a warranty in itself. Disposable items usually carry a LOT instead.

Often confused with

Indicates the manufacturer’s batch code so that the batch or lot can be identified.

More symbols in “Letters”

Sources

ISO 15223-1 is a paid standard, so the wording above is quoted as 3 publishers’ public documents reproduce it. Each was fetched and read on the date shown:

  • Boston Scientific: Symbols Glossary — ISO 15223-1 5.1.7 “Serial number — Indicates the manufacturer’s serial number so that a specific medical device can be identified.” Image labelled ISO 7000-2498. Checked 2026-09-25.
  • NE Scientific: Master Symbol Glossary (CTF-100011 Rev 01) — Shows SN in a box for reference no. 5.1.7 (ISO 7000-2498). Checked 2026-09-25.
  • Stago: Glossary of symbols (520233-A_EN) — “Serial number — Indicates the manufacturer's serial number so that a specific medical device can be identified. NF EN ISO 15223-1, symbol #5.1.7.” Checked 2026-09-25.

Plain-language parts are in our own words; quotations are the sources’ wording.