How to check if a VAT number is valid

When a business sets up a new client or supplier, it is good practice to check the supplier’s VAT number because, if it is invalid, so is the tax invoice they issue, and HMRC may disallow the input tax claim. It is equally important in Northern Ireland when dealing with sales to businesses in other EU Member States, because if a business gets the VAT number wrong it should not zero-rate the sale and HMRC will assess the business if it has.

No doubt the majority of such cases are innocent errors, such as printing mistakes. However, the fraudulent use of another business’s VAT numbers is prevalent in certain sectors of business. In particular, businesses dealing in the supply of computer chips, construction and supplies of labour and scrap metals should validate the VAT numbers of suppliers and customers, as missing trader fraud is common in these business sectors.

How to check a VAT number

To check that a UK VAT number is valid, you should first check that it is nine digits long. A business can verify a UK-registered business’s VAT number through the official Gov.uk VAT Checker. Having gone to the HMRC website (www.gov.uk/check-uk- vat-number), a business enters the VAT number it wants to check.

• It will then confirm if the number is valid and display the registered business name and address.
• If the business is also VAT-registered, it can enter its own VAT number to receive a downloadable certificate as proof of its due diligence.
• Alternatively, a business can call the HMRC VAT helpline at 0300 200 3700 for assistance.

This service allows UK taxpayers to obtain a certificate to prove that they checked that a VAT registration number was valid at a given time and date. This is especially important when a business takes on new suppliers or customers, as if the VAT number is invalid, HMRC could withdraw the business’s ability to reclaim the input VAT it had paid. The certificate will also provide valuable evidence to prove that the trader acted in good faith, should HMRC challenge input tax recovery or seek payment of lost VAT. For businesses in Northern Ireland, checking a VAT
number in an EU member state, they can use the online VAT Information Exchange System (VIES) provided by the European Commission (https:// ec.europa.eu/taxation_customs/vies/#/vat-
validation).

• How to use VIES: Select the country code and enter the VAT number without spaces. Because of the Northern Ireland Protocol, businesses there may use numbers starting with ‘XI’, which can also be checked through VIES for intra-EU transactions.
• While it confirms the validity of the VAT number, it may not always display the business name or address, depending on the specific country’s privacy rules.

Common reasons for ‘invalid’ results:

• Typographical errors: Ensure there are no extra spaces or symbols.
• Newly issued numbers: It can take a few days for a new registration to appear in national databases.
• Inactive numbers: The business may have deregistered or failed to renew its status.

Both the HMRC and VIES VAT checker systems are provided free of charge. Businesses should check a VAT number regularly to ensure that the business has not deregistered from VAT.

Many commercial software accounting providers also supply built-in VAT checkers as part of their packages.

Practical tip

Always save a screenshot or print the validation result for the business’s accounting records. This protects it if HMRC later questions the legitimacy of a supplier’s or customer’s VAT status. Checking a VAT number is essential to ensure legitimate tax compliance, verify the identity of suppliers, and prevent financial fraud. Validating a number protects a business from having VAT reclaims rejected by HMRC, which can lead to denied deductions, financial penalties, and time- consuming audits.

Disclaimer: The information provided on AccountingFirms.co.uk is for general informational purposes only and should not be considered professional accounting, tax, or legal advice. Always consult a qualified accountant or tax adviser for advice tailored to your individual circumstances.