Why the check is mandatory
When supplying goods or services to a company in another member state, the rate is 0% (or reverse charge) only if the recipient has a valid VAT number in VIES on the date of supply. With an invalid number, the National Revenue Agency charges 20% at your expense. Check on every new deal and periodically for regular clients.
Format of the Bulgarian VAT number
BG + UIC (9 digits) for companies, or BG + personal number (10 digits) for individuals. The format did not change with the introduction of the euro. Businesses registered under the EU small-enterprise scheme carry a "-EX" suffix.
If the number is invalid
Ask the counterparty for a registration certificate from their local tax administration. Some countries (Germany, Spain) activate companies in VIES separately from national VAT registration — the number may be real but not yet activated for intra-EU supplies. Invoice at 20% until then.
EU VAT number formats
| Country | Code | Format |
|---|---|---|
| Bulgaria | BG | 9 or 10 digits |
| Germany | DE | 9 digits |
| Romania | RO | 2–10 digits |
| Greece | EL (not GR) | 9 digits |
| Italy | IT | 11 digits |
| Spain | ES | letter/digit + 7 digits + letter/digit |
| France | FR | 2 characters + 9 digits |
| Netherlands | NL | 9 digits + B + 2 digits |
| Austria | AT | U + 8 digits |
| Poland | PL | 10 digits |
| Czechia | CZ | 8–10 digits |
| Ireland | IE | 7 digits + 1–2 letters |
| Northern Ireland | XI | 9 digits (post-Brexit) |
When the check is mandatory
For every intra-EU supply of goods (Art. 7 of the VAT Act) and for services to taxable persons in the EU (Art. 21(2)). The result is kept as proof of the zero rate. For online sales to individuals in the EU, no check is needed — the OSS regime applies there instead. Details: VAT registration, accounting for IT and freelancers, online stores.
Frequently asked questions
Why does the format look valid but VIES shows the number as invalid?
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Format checking only verifies the number of digits and letters — it does not guarantee the number is actively registered. Some countries activate numbers for intra-EU supplies separately from national VAT registration; always confirm in VIES too.
How do I check a VAT number outside the EU?
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VIES only covers EU member states and Northern Ireland (code XI). For numbers outside the EU there is no shared registry — request a registration certificate directly from the counterparty.
What should I do if my client's number turns out to be invalid?
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Invoice with the local VAT rate (20% in Bulgaria) until the number is confirmed in VIES. Ask the client for a registration certificate or wait for the number to be activated.
Sources
VAT Act Art. 7, 21, 94; Regulation (EU) 904/2010; VIES — European Commission. Verified 3 September 2026. The tool checks format only; validity is confirmed exclusively in VIES.