What Is a VAT Number, and How Do I Get One?

A VAT number is the unique identifier a tax authority issues to a business when it registers for VAT. It goes on every invoice, lets your B2B customers apply the reverse charge, and is the key the tax authority uses to track your filings, payments, and audit history. Different countries call it different things (TIN, GST number, TRN, T-number, BTW-id), and the formats vary, but the concept is the same: it is your VAT identity.

This guide explains what a VAT number is, what its format looks like in the major jurisdictions, when you need one, and how to register.

What a VAT number actually is

A VAT number is issued by the tax authority of a single country and is valid only for that country's VAT system. If you operate across multiple countries, you may need multiple VAT numbers (one per country), with the exception of the EU's One-Stop Shop scheme that lets one number cover B2C across the whole EU.

The number serves three jobs:

• Identification: the tax authority knows it is you when you file a return.
• Validation: your business customers can verify you are a registered VAT entity (and therefore can apply reverse charge if you sell B2B cross-border).
• Audit trail: every invoice you issue carries the number; the authority can match invoices to returns.

VAT number formats by country

Knowing the format helps you spot fakes immediately and avoid input errors when capturing customer numbers. Here are the formats for the countries SaaS sellers encounter most often.

European Union

EU VAT numbers begin with the two-letter ISO country code, followed by 2 to 12 alphanumeric characters depending on the Member State. Examples:

• Germany: DE123456789 (DE plus 9 digits)
• France: FRXX123456789 (FR plus 2 alphanumeric plus 9 digits)
• Italy: IT12345678901 (IT plus 11 digits)
• Spain: ESX12345678 (ES plus 1 letter or digit, 7 digits, 1 letter or digit)
• Netherlands: NL123456789B01 (NL plus 9 digits, B, 2 digits)
• Poland: PL1234567890 (PL plus 10 digits)

The full pattern for each Member State is in the EU's TAXUD specification. Validation against VIES checks both format and registration status.

United Kingdom

UK VAT numbers are 9 digits prefixed with GB: GB123456789. Some include a 3-digit branch suffix for divisional registrations: GB123456789012. UK numbers can be checked at HMRC's online lookup.

United States

The US has no VAT and no VAT number. The closest equivalents are the federal Employer Identification Number (EIN) and state-level sales tax permits. EINs are 9 digits in the format XX-XXXXXXX. State sales tax permits are state-issued and have varying formats.

Australia

Australia uses the Australian Business Number (ABN), 11 digits: 12 345 678 901. GST registration is recorded against the ABN. Non-resident SaaS sellers can use a simplified registration that does not require an ABN; instead, an ATO Reference Number (ARN) is issued.

New Zealand

The IRD number is 8 or 9 digits. GST registration is tracked by IRD number plus a separate GST registration confirmation.

Canada

The GST/HST number is the Business Number (9 digits) plus the program identifier RT plus a 4-digit reference: 123456789RT0001.

Japan

The Japanese qualified invoice issuer registration number is the letter T plus 13 digits: T1234567890123. No hyphens or spaces. The format must be exact.

Singapore

The GST registration number is 9 digits ending in a check letter, often presented with the prefix M or S: 200012345M.

UAE

The Tax Registration Number (TRN) is 15 digits: 100123456789003.

Saudi Arabia

The TRN is 15 digits, similar to the UAE. ZATCA's Fatoora system also assigns each invoice a UUID.

India

The Goods and Services Tax Identification Number (GSTIN) is 15 characters: 2 digits for the state code, 10 characters for the PAN, 1 digit for entity number, 1 letter, 1 check digit. Example: 27AAAAA0000A1Z5.

Brazil

The Cadastro Nacional da Pessoa Jurídica (CNPJ) is 14 digits: 12.345.678/0001-95. Used for federal tax including indirect taxes (PIS, COFINS, ICMS at state level uses an additional Inscrição Estadual number).

Mexico

The Registro Federal de Contribuyentes (RFC) is 12 or 13 alphanumeric characters depending on entity type.

For more formats and validation against the official registries, see our free Tax ID Validator.

When you need to register for a VAT number

You need a VAT number when:

• Your domestic business crosses your home country's VAT registration threshold.
• You sell B2C into another country and cross that country's threshold for non-resident sellers.
• You have a fixed establishment (office, warehouse, employees) in another country.
• You receive supplies in another country that trigger a reverse-charge obligation as the recipient.
• You voluntarily register below the threshold to recover input VAT or to look more credible to customers.

The thresholds for non-resident SaaS in 60+ countries are listed in our 2026 thresholds table. The fastest way to see which thresholds you have crossed is the free VAT Exposure Dashboard.

How to register: country-by-country

EU One-Stop Shop (Non-Union OSS for non-EU sellers)

One registration covers B2C digital services to all 27 Member States. Steps:

1. Choose a Member State of identification (any of the 27, but Ireland and Luxembourg are popular for English-language friendliness).
2. Apply through that Member State's tax portal.
3. Receive your OSS-specific VAT number (typically the country code EU followed by digits).
4. Start filing quarterly OSS returns covering all 27 Member States.

OSS does not cover B2B (which is reverse charge anyway) or non-digital goods (which use the IOSS scheme).

EU Member State (full local registration)

If you have a fixed establishment or sell physical goods, you may need full registration in a Member State. Each has its own portal and language. Most accept English documentation; processing time ranges from 2 weeks (Ireland, Netherlands) to 3 months (Italy, Greece).

United Kingdom

Register through HMRC's online portal. Steps:

1. Create a Government Gateway ID for your business.
2. Apply for VAT registration online.
3. Provide business details, expected turnover, bank details.
4. Receive a VAT number, typically within 2 to 4 weeks. The certificate arrives by post.

For non-resident SaaS sellers, no UK threshold applies; registration is required from the first sale to a UK consumer. See our UK VAT registration walkthrough.

Australia

Two registration paths:

1. Standard ABN-based GST registration (for businesses with Australian operations).
2. Simplified GST registration (ARN-based, for non-resident digital service providers).

Simplified registration is online via the ATO portal, typically completed within 7 days. The threshold is A$75,000 in 12 months.

Canada

Simplified GST/HST registration for non-residents is available through CRA's online portal. The threshold is C$30,000 in 12 months. Once registered, you charge a destination-province blended rate. See our Canada walkthrough.

Japan

Foreign businesses register for the qualified invoice issuer regime through the National Tax Agency (NTA). The number issued is in the format T plus 13 digits and must appear on every invoice. See our Japan JCT guide.

UAE

Federal Tax Authority registration via the EmaraTax portal. No threshold for non-resident sellers; registration required from the first taxable supply. The TRN is 15 digits. See our UAE guide.

Other major jurisdictions

Singapore, India (OIDAR), South Africa, Mexico, Norway, Switzerland, Saudi Arabia all have non-resident registration paths, mostly online. Country-specific guides are linked from the US SaaS global VAT guide.

What to expect after you register

Once registered, you have ongoing obligations:

• Charge VAT: apply the local rate to taxable supplies starting on the registration effective date.
• Issue compliant invoices: include your new VAT number, the destination country's required fields, and the right narratives. See VAT invoice wording.
• File returns: monthly, quarterly, or annual depending on the country. Track them with the filing calendar.
• Pay VAT: by the due date for each return. Cross-border wire transfers can take time, so build a buffer.
• Keep records: 5 to 10 years depending on the country.
• Validate B2B customer numbers: use the tax ID validator for every reverse-charge invoice.

What if I do not need a number anywhere?

If you are below all relevant thresholds and have no permanent establishment outside your home country, you may not need any non-domestic VAT number. But monitor regularly. Thresholds for B2C digital services are low: A$75,000 (Australia), C$30,000 (Canada), zero (UK, Norway, UAE for non-resident digital). One year of growth often pushes a SaaS company across two or three thresholds simultaneously.

Use the free exposure dashboard monthly to see where you are in each country and how close to thresholds you are running.

Common mistakes to avoid

1. Buying a "VAT number from a service" that is actually someone else's. Some shady services sell access to a fiscal representative's number rather than registering you properly. The number on the invoice is not yours; the tax authority can void the registration. Always register in your own name through the official portal.
2. Putting the wrong number on invoices. An invoice with the wrong VAT number can be rejected by the customer's tax authority. Test invoices through your accounting system after registration to confirm the right number flows through.
3. Forgetting that EU OSS does not give you a "real" VAT number for that country. The OSS number is for the OSS scheme only; it cannot be used to recover input VAT incurred in those countries. For input VAT recovery you need full local registration or the 13th Directive refund process.
4. Treating the number as confidential. VAT numbers are public information. Putting yours on every invoice, your website, and your contracts is the norm.
5. Not deregistering when you stop trading. Most jurisdictions require active deregistration. Numbers that go dormant accumulate filing obligations and penalties.

Recap

• A VAT number is the tax authority's identifier for your business in their VAT system.
• Each country issues its own with its own format. The EU's OSS scheme covers B2C across 27 Member States with one registration.
• You need one when you cross a registration threshold in a country, have a fixed establishment there, or voluntarily opt in.
• Registration is online in most major jurisdictions; processing time runs from days to a few months.
• Once you have it, the number goes on every invoice, you charge the local VAT rate, and you file local returns.
• Validate other businesses' numbers with the free Tax ID Validator.