Irish VAT Number: Format, Thresholds, How to Verify

Ireland is one of the few countries where the VAT registration threshold depends on what you sell, not just how much.

Get the classification wrong and you register a year late, with the liability backdated.

The short answer

The two thresholds, and the 90% rule

This is the part that is specific to Ireland and the part that goes wrong.

A business supplying both takes the goods threshold if 90% or more of turnover comes from goods. Otherwise it takes the services threshold.

Why this matters in practice:

1. A consultancy hits its threshold at half the turnover a product business does
2. A product business with a meaningful service line, say 15% of revenue, drops to the lower threshold entirely
3. The measurement is a rolling twelve months, not a calendar or accounting year

The rolling window is the trap. A business that is comfortably under the threshold on 31 December can be over it on 14 March, because the window moved. Watching the calendar year is not the same as watching the threshold.

What the letters mean

The Irish format ends in letters, which is unusual in the EU and confuses validation systems.

• One letter, as in IE1234567T, is the older style
• Two letters, as in IE1234567FA, is the format issued since 2013
• Both remain valid. An old number was not reissued in the new format

Practical consequence: a validation form or database that assumes a fixed length will reject one of the two. If an Irish VAT number is failing a format check, the length is the first thing to look at, not the digits.

Older style, still valid

IECountry prefix

12345677 digits

TOne letter

Never reissued in the new format, so plenty of these are still in circulation.

Issued since 2013

IECountry prefix

12345677 digits

FATwo letters

A validator that assumes one fixed length will reject one of these two. Check the length before the digits.

Which Irish number is which

An Irish company accumulates identifiers, and the VAT number is only one of them.

The TRN and the VAT number are both Revenue numbers, which is why they get confused. A form asking for a "tax registration number" is not necessarily asking for the VAT number, and only the VAT number is externally verifiable.

How to verify one

VIES, the European Commission's validation service, is the authoritative route and it is free.

What it does:

• Confirms whether the number is valid on the day you check
• Returns the registered name and address
• Issues a consultation number, which is your evidence that you checked

Three rules for using it properly:

1. Validate the number, not the invoice. A VAT number printed on a PDF proves nothing about its status
2. Check on the date of supply, not once at onboarding. Registrations get cancelled
3. Keep the consultation number. If a zero-rated supply is challenged, the record of the check is what protects you

That third point is the commercial reason this matters. If you zero-rate an intra-EU B2B supply against a number that was invalid at the time, the VAT liability is yours, not the customer's. The consultation number is the difference between a defensible position and an assessment.

When an Irish VAT number does not validate

Five causes, in order of likelihood:

1. The business is not VAT registered. Below both thresholds and not registered voluntarily
2. You have the CRO number. Purely numeric, no IE prefix, different register
3. The trailing letters were dropped, often by a system that expected digits only
4. Registration was cancelled. Revenue deregisters inactive traders
5. The number is transposed. Seven digits and no obvious check character

Registering before you have to

Voluntary registration is available below the thresholds, and it is a genuine trade-off.

For: input VAT recovery, and EU B2B customers who expect a valid number.

Against: periodic returns for as long as you stay registered, and VAT added to prices if your customers are consumers who cannot reclaim it.

For a services business selling to Irish consumers, voluntary registration below 42,500 EUR usually makes you more expensive without making you more credible.

Whether the VAT position works in your favour is one of the questions worth settling before incorporating rather than after, alongside the other running obligations of an Irish company.

The summary