A VAT ID, or value-added tax identification number, is a unique code that a national tax authority assigns to a business registered to collect value-added tax. More than 170 countries operate a VAT or an equivalent system (often called GST), and any business selling goods or services into one of them will likely need a number at some point.1OECD. VAT Policy and Administration Without a valid one, you cannot reclaim the tax you pay on business purchases, your cross-border customers cannot zero-rate their sales to you, and you risk penalties that in some jurisdictions reach into six figures.
What the Number Actually Does
VAT is collected at every stage of a supply chain, not just at the final sale to a consumer. When your business buys raw materials, you pay VAT on that purchase (input VAT). When you sell a finished product, you charge VAT to your customer (output VAT). You subtract the input from the output and send the difference to the tax authority. Because each buyer claims a credit for tax already paid, every transaction gets reported from both sides.
Your VAT ID is what makes that chain work. It tells the tax authority which business collected the output VAT, which business is claiming the input credit, and whether both numbers are currently valid. It also lets your trading partners confirm you are a registered, taxable business before they apply special tax treatment to a cross-border sale. On an invoice, the number is the piece of information that unlocks zero-rating, reverse charge treatment, and input recovery on the other side.
What a VAT ID Looks Like
In the European Union, every VAT ID starts with a two-letter country code: DE for Germany, FR for France, IT for Italy. After the prefix comes a string of characters whose length depends on the country. A French number has 11 characters after the prefix (two letters plus nine digits). Irish numbers run to eight or nine characters. German numbers are always nine digits. Swedish numbers run to 12.2European Union Intellectual Property Office (EUIPO). VAT Numbers EU
Outside the EU, formats vary more. The UK uses the prefix GB followed by nine digits, or 12 for certain government entities. Australia does not use a traditional VAT ID at all; businesses register for an Australian Business Number (ABN) and separately register for GST through the same system.3Australian Government ABN Lookup. ABN Lookup Home The purpose is always the same: a machine-readable code that links a business to its tax authority and enables automated validation.
Who Needs One
Two things typically trigger a registration requirement: crossing a domestic turnover threshold, or engaging in certain kinds of cross-border activity.
Domestic Thresholds
Most countries set an annual revenue level above which registration becomes mandatory. In the UK, that threshold is £90,000 in taxable turnover.4GOV.UK. How VAT Works: VAT Thresholds In France, it is €85,000 for goods and accommodations or €37,500 for services. Some countries set no threshold at all, meaning every business making taxable supplies must register regardless of size. Below the threshold, registration is usually voluntary, but many businesses opt in anyway because a VAT ID lets them reclaim input VAT on purchases.
Cross-Border Sellers From Outside the EU
If your business is based in the United States and you sell digital services, streaming subscriptions, software, or other electronically supplied products to individual consumers in the EU, you must register. There is no minimum threshold for non-EU sellers. Even a single sale to an EU consumer creates an obligation.5European Commission. VAT e-Commerce – One Stop Shop The same applies if you store inventory in an EU country or import goods for sale to EU consumers.
Business-to-business services work differently. Most cross-border B2B service transactions shift the VAT obligation to the buyer through the reverse charge: you invoice without VAT, and your customer self-assesses the tax on their own return, recording it as both output VAT owed and input VAT reclaimable so the two entries cancel out. You still need a VAT ID to identify yourself on the invoice and you need to confirm your customer’s number is valid, but you may not need to register in every country where your business customers sit.
A Note on the EU Small Business Exemption
Since January 2025, the EU has operated a cross-border small business exemption. A business established in an EU member state with total EU-wide turnover of no more than €100,000 can apply for VAT exemption in other member states, provided the national threshold in the destination country is no higher than €85,000.6European Commission. VAT Rules for Small Enterprises – SME Scheme It does not apply to businesses established outside the EU.
Getting a Number as a U.S. Business
Registration is handled by the tax authority in the country where you need the number. For a U.S. software company or SaaS provider selling subscriptions to individual European consumers, the EU’s One Stop Shop (OSS) is the usual route. Before 2021, a company selling into 10 EU countries needed 10 separate registrations. Under the non-union OSS scheme, you pick any single EU member state, register there, and file one quarterly VAT return covering all your B2C service sales across the entire EU.7European Commission. Register to OSS
The member state you pick assigns a special number in the format EUxxxyyyyyz. It works only for transactions reported through the OSS. If you also hold inventory in a specific country or have other local obligations, you still need a standard registration there.8European Union. EU VAT One Stop Shop (OSS) The OSS registration takes effect on the first day of the quarter after your application, though you can start earlier if you notify the tax authority within 10 days of your first sale.7European Commission. Register to OSS
A standard (non-OSS) registration is heavier. Expect to submit proof that your company legally exists, evidence of planned commercial activity in the jurisdiction, and identification documents for company directors. Processing times range from a few days for straightforward online applications to several weeks for non-resident businesses that require manual review. Government tax authorities generally do not charge a fee for the registration itself; the real cost is indirect, coming from professional advisors, document translation, and fiscal representative fees.
Fiscal Representation
More than half of EU member states require non-EU businesses to appoint a fiscal representative: a local entity that takes on joint liability for your VAT obligations. The representative posts a financial guarantee with the tax authority, verifies your documentation, and faces penalties if your returns are inaccurate. Norway, Switzerland, and Japan impose similar requirements. Factor this cost into your planning before entering a new market. Some countries offer a lighter alternative called a “fiscal agent” that handles administrative filings without assuming full liability, but availability varies.
Verifying a Trading Partner’s Number
Before you zero-rate a cross-border sale, confirm your customer’s VAT ID is genuine and currently active. If the number turns out to be invalid, the tax authority can hold you liable for the uncollected VAT, turning what you thought was a tax-free sale into an expensive mistake.
The VAT Information Exchange System (VIES) is the European Commission’s official tool for checking EU numbers. You enter the number and VIES confirms whether it is valid and currently associated with an active, taxable business.9European Union. Check a VAT Number (VIES) What VIES shows beyond that depends on the member state. Some display the registered business name and address directly; others, citing data protection rules, will only confirm whether a name and address you provide match the number on file. If VIES doesn’t give you what you need, you can request confirmation from the relevant national tax authority.
The UK runs its own verification service at GOV.UK, where you can check whether a UK number is valid and see the registered business name and address.10GOV.UK. Check a UK VAT Number Australia’s ABN Lookup provides similar functionality for GST-registered businesses.3Australian Government ABN Lookup. ABN Lookup Home Save the result whichever tool you use. Tax auditors expect documented proof that you validated your customer’s number before applying zero-rate treatment. A screenshot or system-generated confirmation with a timestamp is standard practice.
What Happens If You Skip It
The consequences of non-compliance go well beyond a late fee. Tax authorities can backdate your VAT liability to the moment you crossed the registration threshold, meaning you owe VAT on every sale you made between that date and the day you actually registered. You are unlikely to recover that cost from your customers after the fact.
Country-specific penalties vary. In Germany, late filing penalties can reach 10% of the VAT due, capped at €25,000 per return, plus 1% monthly interest on the unpaid balance. France can impose surcharges of 10% to 40% on understated amounts, jumping to 80% for fraud, alongside potential criminal penalties including fines exceeding €75,000 and prison time of up to five years. At the extreme end, prolonged non-compliance can result in your VAT registration being revoked entirely, which effectively locks you out of that market.
If your sales are trending toward a country’s threshold, voluntary registration ahead of time costs nothing in government fees and lets you start reclaiming input VAT immediately. Waiting until the last possible moment creates the kind of tight deadline where mistakes happen.