Winkel Factuur Insights
An incorrect IBAN number on your invoice can lead to failed payments, delays, and frustration. With an IBAN validator, you can quickly check whether an account number is correct. In this article, we explain how IBAN works, what can go wrong, and how to use our free IBAN checker to prevent problems.
IBAN validation checks the country code, bank code, and check digits of an account number to verify it is structurally correct before you process a payment.
Invalid IBAN numbers on invoices cause failed payments, delayed cash flow, and manual correction work. Validate IBAN numbers before they reach your invoices using our free checker, and automate validation in your invoicing workflow.
IBAN (International Bank Account Number) is the international standard format for bank account numbers. Since 2014, IBAN has been mandatory for all payments within the EU and EEA.
Why IBAN?
• International: One format for all European banks
• Error detection: Built-in check for typos
• Automation: Faster processing of payments
• Security: Reduces risk of wrong transfers
IBAN on invoices:
As a business owner, you must include your IBAN on invoices so customers can pay. An error in this number means payments don't arrive or are returned.
An IBAN consists of different components that together are unique for each bank account.
IBAN structure example (18 characters):
NL91 ABNA 0417 1643 00
• NL = Country code (Netherlands)
• 91 = Check digits (calculated from the rest)
• ABNA = Bank code
• 0417164300 = Account number
IBAN length by country:
• Netherlands: 18 characters
• Belgium: 16 characters
• Germany: 22 characters
• France: 27 characters
• United Kingdom: 22 characters
The check digits:
The two digits after the country code are check digits. These are calculated using a mathematical formula (modulo 97). This allows typos to be detected.
Test all features without credit card. Automatic invoices within minutes.
Start free trial →Despite error detection, things regularly go wrong with IBAN numbers. These are the most common problems:
1. Typos
Swapping digits or letters. For example, 0 and O, or 1 and l.
2. Wrong country code
Entering the wrong country code for foreign accounts.
3. Incorrect spacing
Some systems require spaces, others don't. This can cause confusion.
4. Old account number
Using old domestic account numbers instead of IBAN.
5. Copy-paste errors
When copying, extra spaces or characters can be included.
Solution: Always check IBAN numbers with our free IBAN validator before using them on invoices.
Our free IBAN validator performs multiple checks to determine if an IBAN is valid.
What does the validator check?
• Format: Is the length correct for the specified country?
• Country code: Is the country code valid (ISO 3166)?
• Check digits: Is the modulo-97 calculation correct?
• Bank code: Is the bank code known?
• Structure: Do all characters meet country-specific rules?
What do you get back?
• ✅ Confirmation whether the IBAN is valid
• 🏦 Name of the bank (if known)
• 🌍 Country of the account
• 📋 BIC/SWIFT code of the bank
Besides IBAN, you often encounter the term BIC or SWIFT. What's the difference?
IBAN:
Identifies the specific bank account. Comparable to your home address.
BIC (Bank Identifier Code) / SWIFT:
Identifies the bank itself. Comparable to the name of your city.
Example:
• IBAN: NL91 ABNA 0417 1643 00
• BIC: ABNANL2A
When do you need BIC?
• For payments outside the EU (SEPA zone)
• For some international transfers
• When the payment system asks for it
Within the EU (SEPA zone), only IBAN is usually sufficient. Our IBAN validator automatically shows the corresponding BIC code.
Correctly displaying your IBAN on invoices is essential for timely payments.
Tips for IBAN on invoices:
• Clearly visible: Place the IBAN prominently, not hidden at the bottom
• Correct format: Use spaces for readability: NL91 ABNA 0417 1643 00
• Verified: Validate your own IBAN before sending invoices
• Consistent: Always use the same IBAN on all your invoices
With our free invoice maker, you enter your IBAN once and it's correctly formatted on all your invoices.
What if your IBAN changes?
Inform all your customers well in advance. Old outstanding invoices remain valid with the old IBAN, new invoices get the new number.
Do you work with foreign suppliers or customers? Then you'll encounter international IBAN numbers.
Common countries and their IBAN format:
• Belgium: BE68 5390 0754 7034 (16 characters)
• Germany: DE89 3704 0044 0532 0130 00 (22 characters)
• France: FR14 2004 1010 0505 0001 3M02 606 (27 characters)
• Spain: ES91 2100 0418 4502 0005 1332 (24 characters)
• Italy: IT60 X054 2811 1010 0000 0123 456 (27 characters)
Note with international IBAN:
• Length varies by country
• Some countries also use letters in the account number
• Always check with a validator before paying
Our IBAN validator supports IBAN numbers from all countries.
Can I still use my old account number?
No, since 2014 IBAN has been mandatory for all payments in the EU. Your old domestic account number no longer works.
What if the IBAN validator says my number is invalid?
Check that you've copied the number correctly. No extra spaces, no swapped characters. If the problem persists, contact your bank.
Is it safe to share my IBAN?
Yes, sharing your IBAN is safe. People cannot simply withdraw money with just your IBAN. A direct debit authorization is also required.
How long does a SEPA transfer take?
Within the EU, a SEPA transfer must be processed within 1 business day. With correct IBAN details, this usually goes smoothly.
What does a wrong IBAN cost?
A transfer to a wrong IBAN can be returned, but this can take days to weeks and there may be costs involved.
Prevent payment problems and validate IBAN numbers with our free tool.
• Check domestic and international IBAN numbers
• Instant result: valid or invalid
• Shows bank name and BIC code
• 100% free, no registration required
• Your data is not stored
Other useful tools:
• Invoice Creator - Create invoices with correct IBAN format
• VAT Calculator - Calculate VAT amounts
• Credit Note Creator - Create credit notes
All our tools are free and respect your privacy.
IBAN (International Bank Account Number) is the international standard format for bank account numbers, mandatory for all EU payments since 2014. Including a correct IBAN on your invoices ensures customers can pay without errors or delays.
IBAN length varies by country. Dutch IBANs have 18 characters, Belgian 16, German 22, and French 27 characters. Each IBAN contains a country code, check digits, bank code, and account number.
Yes. Sharing your IBAN is safe. With just your IBAN, no one can withdraw money from your account. A direct debit authorization is also required for automatic debits. Displaying your IBAN on invoices is standard business practice.
IBAN identifies the specific bank account, like a home address. BIC (Bank Identifier Code) identifies the bank itself, like the name of the city. Within the EU (SEPA zone), usually only the IBAN is needed. BIC may be required for payments outside the EU.
A payment to a wrong IBAN may be returned if the number does not exist, but this can take days to weeks and may involve fees. If the number exists but belongs to someone else, recovering the money requires contacting your bank and can be difficult.