One of the most common questions we hear from customers is: "How often should we actually be revalidating tax IDs?"

The answer, as usual with tax matters: it depends. That is exactly why we reached out to all tax authorities of the major economies around the world to ask what the official expectation was. By the time you get to the bottom of this page, you will find their exact written responses.

Everyone knows tax data needs to stay current. The question is what "current" actually means to different tax authorities.

To get clarity, we reached out directly to tax authorities across 20+ jurisdictions and asked them what they expect. Their responses reveal a surprisingly wide range of requirements, from Slovakia's mandate to verify every single transaction to Jamaica's approach of leaving frequency entirely to taxpayer discretion.

Here's what tax authorities actually told us about revalidation timing.

Important note: This article shares guidance provided directly by tax authorities as of December 2025. It is not legal or tax advice. Businesses should consult with qualified tax advisors and the tax authorities directly about their specific situations and compliance obligations. We'll continue updating this article as we receive guidance from additional jurisdictions.

Why revalidation requirements matter for multi-country operations

If you're operating across multiple jurisdictions, you're managing conflicting compliance standards. Manual processes can't scale when some tax authorities expect real-time verification. The compliance risk compounds with each additional country: Miss Norway's invoice-receipt timing requirement while focused on France's periodic schedule, and you're exposed to denied deductions and penalties across your transaction volume.

Countries requiring tax ID validation for every transaction

These jurisdictions have the strictest requirements, creating the most immediate compliance risk if you're operating there:

Slovakia: Tax ID validation required at the time tax liability arises

Validation is required by law for every transaction at the time tax liability arises (on supply of goods/services or when payment is received prior to supply).

Non-compliance results in refusal of exemption, additional VAT payments, reduction of excess VAT deductions, and sanctions.

Belgium: VAT must be applied correctly at each taxable event

VAT legislation must always be applied correctly. Whenever a taxable event occurs where the customer's status could impact VAT application, this must be verified.

Spain: Customer check recommended for each transaction

To ensure correct taxation of the transaction, you should carry out the customer check for each transaction (though in principle, companies can verify whenever they deem appropriate based on transaction frequency).

Denmark: VAT numbers must be validated for each EU sale

Companies must validate VAT numbers for each sale to another EU country.

When you validate the VAT number, you should take a screenshot as documentation and attach it to your receipts. These records must be kept for 5 years.

Norway: VAT register must be checked upon invoice receipt

The duty of care requires buyers to check the seller's registration status in the VAT Register when each specific invoice is received.

Previous checks (for example, once per quarter) are not sufficient if new transactions or invoices occur in the meantime. If circumstances create doubt about registration status, buyers must perform a new check in public registers.

Hungary: Status must be examined for each supply

VAT obligations must be determined for each supply and each transaction separately. This means examining whether the counterparty's taxable person status exists for each transaction.

While this principle applies even in ongoing business relationships, it must be balanced with whether the invoicing taxable person acted with due care and took all reasonably expected measures to avoid participation in tax evasion.

Countries with risk-based and periodic tax ID revalidation guidance

These tax authorities recommend verification timing based on transaction frequency, volume, and risk factors:

France: Data entry and scheduled periodic checks

The general recommendation is verification at data entry when adding a new partner, customer, or supplier. After that, schedule regular periodic checks to spot changes like company status updates, number extinctions, or data updates.

Set up automatic alerts when periodic checks detect inconsistencies requiring action.

Regarding frequency: quarterly or monthly verification for frequent transactions, verification before each transaction for one-off transactions or new businesses.

Canada: Verify at relationship start and periodically

While there's no specific CRA-mandated frequency, businesses should verify the tax identification number when establishing a new business relationship and periodically thereafter, especially if the buyer's information changes or if there's reason to doubt TIN validity.

For GST/HST purposes, confirming the buyer's registration number at the time of transaction is important. Regular checks help prevent errors in tax reporting and potential penalties.

Finland: Valid VAT number required for exemption

A valid VAT number is a precondition for VAT exemption in intra-community trade. If the seller reports intra-community sales and the purchaser's VAT ID number is not valid, the Finnish Tax Administration may deny the VAT exemption, impose sale VAT on the transaction, and add a 10% tax increase.

The Tax Administration strongly recommends checking the validity of the counterpart's VAT number before sending the first invoice and checking it regularly while doing business.

If errors are discovered later, both parties must proactively correct any recapitulative statements and VAT returns within 3 years (though corrections should be made without delay when noticed).

Estonia: KYC principle for VAT ID checks

Companies are expected to know their business partners and ensure they're trustworthy. When starting cooperation with a new partner, check their VAT ID before the first transaction.

It's also recommended to occasionally recheck VAT numbers of long-term partners, especially if there are doubts or signs that something might not be right with the company.

Companies that cooperate with unreliable partners must be prepared to be jointly responsible for the transactions they make.

Czech Republic: Status required on taxable supply date

It's the responsibility of VAT-registered persons to know whether their business partners are VAT-registered or not, which enables proper assessment of VAT liability.

You must know the status on the date of the taxable supply (generally the date of supply or receipt of payment before supply). Recipients claiming VAT deductions must verify their business partner's VAT ID on the taxable supply date.

If recipients don't check their supplier's VAT ID, they risk unjustified VAT deduction if the taxable supply date is incorrect. Taxpayers decide how to set up their internal systems to automatically verify business partners' VAT IDs.

Bulgaria: Typically monthly with VAT return

Verification is done when necessary to ensure correct reflection of the VAT register. Most often this is monthly, when submitting a VAT return.

Lithuania: Due diligence and fraud risk assessment

The State Tax Inspectorate recommends following the "know your customer" principle. When planning and carrying out transactions, choose partners carefully and assess the circumstances of each transaction to avoid becoming involved in fraudulent schemes.

Traders are expected to take all reasonable measures to avoid being drawn into transaction chains where VAT is being evaded.

Assessing risks and implementing appropriate due diligence procedures for potential partners can reduce the likelihood of negative tax consequences. Non-confidential information about business partners can be checked directly on the VMI website.

Poland: VAT due diligence methodology

Due diligence in VAT is outlined in the "Methodology for assessing the due diligence exercised by purchasers of goods in domestic transactions." This applies to purchasers who didn't commit VAT fraud and were unaware their transaction was used for fraud.

Taking the actions indicated in the Methodology significantly increases the likelihood of exercising due diligence and receiving a VAT refund.

Latvia: Regular checks recommended

While verification is not mandatory in all cases, it's recommended to ensure compliance with VAT regulations and avoid tax risks.

Check before starting a transaction with a new customer or supplier, regularly (especially if transactions are frequent or of high volume), and before submitting VAT returns to ensure data accuracy.

Possible consequences of not verifying: financial sanctions for incorrectly provided or invalid VAT numbers, denial of tax deductions if the business partner's VAT status is invalid, and administrative difficulties with invoice processing, VAT reporting, and cross-border transaction documentation.

Kenya: Mandatory PIN and VAT status verification

Before engaging in any transactions with a business person or institution, you're required to request their PIN Number and Tax Compliance Certificate.

You're advised to visit the Kenya Revenue Authority website and verify the status of the PIN (especially the VAT status) through the PIN Checker, and the TCC through the TCC/Exemption/Excise License Checker.

Under the Tax Procedures Act 2015 and the Value Added Tax Act 2013, businesses are required to ensure that transactions are conducted with validly registered taxpayers, particularly when claiming input VAT or charging VAT on taxable supplies.

Serbia: Registration status must be confirmed

On the Tax Administration website, you can check at any time whether the legal entity with which you have cooperation is active.

Legal entities that have been closed or have some kind of measure prohibiting the performance of activities cannot perform activities, make payments from their account, or perform activities.

Countries leaving tax ID revalidation frequency to business discretion

These jurisdictions leave revalidation frequency to business judgment:

Dominican Republic

Currently there is only one regulation requiring verification of tax receipts' validity upon receiving goods or services from a supplier.

However, there's no regulation requiring verification of suppliers' status; this is left to each taxpayer's discretion based on their individual needs. The frequency of verification will depend on the level of scrutiny you wish to exercise when acquiring goods or services from suppliers.

Jamaica

A Taxpayer Registration Number is a permanent unique nine-digit identification number assigned to individuals or organizations when conducting business transactions with tax departments, government agencies, or other institutions.

There is no legal requirement or official guidance in Jamaica that dictates the frequency a supplier must validate a TRN. Validation of TRNs must be the responsibility of the company conducting business based on the company's best practices and policy.

How to automate tax ID revalidation across multiple jurisdictions

Fonoa's tax ID validation can help you meet every country's specific requirements, from Spain's per-transaction recommendation to France's risk-based periodic approach.

Frequently asked questions about tax ID revalidation

Is VAT number validation required for every transaction?

In some countries, yes.

Slovakia requires validation by law for every transaction at the time the tax liability arises. Denmark requires validation for each EU cross-border sale. Norway expects buyers to check VAT registration when each invoice is received. Hungary and the Czech Republic also require VAT status to be assessed on the date of each taxable supply.

Other jurisdictions apply a risk-based or discretionary approach.

The practical takeaway is simple. The more frequently you validate, the more confident you can be that your VAT treatment is correct and that you are not exposed to denied exemptions, rejected invoices or unexpected VAT liabilities. The full article breaks down how this differs across 20+ jurisdictions.

How often should VAT numbers be checked?

There is no single global standard.

Many countries expect verification at onboarding and then periodic revalidation. France, for example, recommends checking when adding a new partner and then performing regular checks based on transaction frequency. Canada and Finland follow similar logic, combining initial validation with ongoing monitoring. Some countries align checks with VAT return cycles.

In stricter jurisdictions, periodic checks alone may not be enough if transactions continue between validations.

As a rule, the higher the transaction volume or risk, the more frequently you should revalidate. Doing so reduces the chance of applying incorrect VAT treatment and strengthens your position in the event of an audit.

Can periodic verification be enough?

In risk-based jurisdictions, yes, provided it reflects transaction frequency and risk.

Countries such as France, Canada, Estonia and Latvia support structured periodic revalidation alongside onboarding checks. However, in countries where verification is expected at each taxable event, periodic checks alone will not meet expectations.

Even where not legally required for every transaction, more frequent validation increases certainty. It helps ensure VAT exemptions remain valid, deductions are defensible and invoices are not later challenged. The article explains where periodic verification works and where it does not.

What documentation should businesses keep?

Businesses should retain clear evidence of when and how validation was performed.

Denmark explicitly requires companies to take a screenshot when validating a VAT number, attach it to receipts and retain the records for five years. More broadly, maintaining screenshots, system logs or automated validation records demonstrates due diligence.

Strong documentation does more than satisfy formal requirements. It provides proof that VAT treatment was based on valid data at the time of the transaction, reducing the risk of denied deductions or retroactive VAT assessments.

Do tax authorities provide official guidance on revalidation?

Yes, though it can depend on the country. The article is based on direct written responses from tax authorities across more than 20 jurisdictions.

Some provide strict, transaction-level rules. Others outline principle-based expectations around due diligence. A few leave frequency to the taxpayer’s discretion.

What they share is a common expectation that tax data must stay current. The closer your validation timing is to the transaction itself, the lower your exposure to VAT errors, rejected invoices and compliance risk. For a country-by-country breakdown, see the full guidance above.

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