How to identify a key
Read the code stamped on a key blank, tell a keyway from an FCC ID, and find the right blank. A practical guide for the trade.
Almost every key carries the information needed to replace it. This is how to read it, and what each kind of code actually tells you.
Where to look
- On the blade, near the shoulder or the bow: the keyway or blank reference, for example HU92, KW1, SC1, TOY43 or HON66.
- On the back of a remote or fob: the FCC ID, usually beginning FCC ID followed by a mixed code.
- On the circuit board inside a fob, if the case has no marking: the OEM part number.
- Stamped on the lock face on some commercial hardware, giving the keyway family directly.
The four kinds of code, and what each proves
| Code | Looks like | What it identifies |
|---|---|---|
| Keyway or blank reference | HU92, KW1, SC1, B111 | The blade profile. Tells you which blank fits the lock, nothing about electronics. |
| FCC ID | KR55WK49622, M3N-A2C31243300 | The radio module. Decisive for a remote, and the single most reliable code to search. |
| OEM part number | 13500221, 89904-06140 | The exact factory part. Narrowest match of all when you have it. |
| Transponder chip | ID46, ID48, 4D63, H chip | The immobiliser chip. Determines whether a key can be programmed to the vehicle. |
Search the code, not the car
A year, make and model narrows a key to a family. A code narrows it to a part. Where the two disagree, trust the code: the same model year often shipped more than one keyway or more than one frequency depending on trim and region.
Paste any of the four codes above into Identify a key and it will show what we hold against it.
When the key has no marking
Unmarked blades are common on aftermarket copies. Two routes: match the profile against a blank chart by eye, or read the lock rather than the key with a 2-in-1 pick and decoder. Our locksmith tools range covers the decoders for most common keyways.
Questions
Is the keyway the same as the key code?
No, and confusing them is the most common ordering error. The keyway is the blade profile, for example HU92. A key code is the cut depth sequence, which a locksmith derives from the lock or from the vehicle. A blank is ordered by keyway.
Two listings show different FCC IDs for my car. Which is right?
Both may be. Manufacturers change radio modules mid-cycle. Read the code off the fob in your hand and match that.
Can you tell me what key my car takes?
We can tell you what we stock for the make. We do not publish year and model fitment tables, because we do not hold verified data for them, and a confident wrong answer costs you a cut blank.
About this guide
This is general information about how the work is normally done, not advice for the particular vehicle, lock or machine in front of you. It does not replace manufacturer instructions, training, or your own judgement about whether a job is within your competence. Specifications and fitment change between model years, so check the code on the original part before you buy or cut anything. See the terms.