Initial letter
Identifies the taxpayer's broad category according to the published pattern.
04 · Free toolFiscal authority: Govern d'Andorra — Departament de Tributs i de Fronteres
NRT format checker
Paste an NRT and see if it has the correct form and what type of taxpayer its initial letter indicates.
It works in your browser. We don't save anything and you don't need to register.
01
How it works
It checks that the number follows the format of one letter, six digits and a check letter, then normalises hyphens and spaces. The initial letter indicates the relevant taxpayer category.
When it helps
- To validate the format of an NRT received by email before adding it to an invoice.
- To detect the most common error: a Spanish NIF pasted into the NRT field because they are similar enough.
- To understand what the initial letter means and what type of taxpayer it identifies.
When it's not enough
- It checks the format, not whether the number exists. A well-formed NRT may belong to nobody; actual verification must be made with the tax authority.
- It checks one NRT at a time. If you manage a client portfolio, the format should be validated when each record is saved so you never need to revisit it.
What it does not do
It checks the format and nothing else. It doesn't tell you if the number exists, if it's registered or if the company is active: for that you have to consult the official sources. A well-formed NRT may not correspond to anyone.
02 · Understanding the NRT
What an Andorran NRT format check actually proves
The checker separates the visible structure of the number. It does not query a register or calculate whether the final letter belongs to the digits.
Six digits
Form the numeric part of the registration number. There must be exactly six.
Final letter
Completes the format. This tool checks that it is present, but not its administrative assignment.
Format examples
These are fictional examples for explaining the structure. They do not identify real taxpayers.
- L-712345-C
- Company format
- F-123456-A
- Individual format
- U-654321-B
- Non-resident format
03 · NRT questionsOfficial source: Govern d'Andorra — Departament de Tributs i de Fronteres
Format, existence and use on invoices
What format does an Andorran NRT use?
The pattern checked here is one initial letter, six digits and one final letter. Hyphens or spaces are accepted as separators and the result is normalised.
Does a valid format mean the company exists?
No. The check validates only the text structure. It does not query the taxpayer census, Companies Register or the company's activity status.
Can I put the result straight onto an invoice?
Use it to catch formatting errors, but confirm the NRT against an official document or with the client before issuing. A well-formed number can still be wrong.
Is an NRT the same as a Spanish NIF?
No. The NRT is Andorra's tax identifier. A foreign tax identifier must not be converted or pasted into the NRT field because it looks similar.
To confirm existence, ownership or status, use the taxpayer's documents or the relevant official channel. AndCompta does not present this format check as a register lookup.
What if you never had to do it by hand again?
In AndCompta, a customer’s NRT is saved once and never needs to be entered again.