To check that a UK VAT number is valid you should first check that it is 9 digits long. (This does not include the GB which is sometimes stated at the beginning). The first 7 digits are random numbers and the last 2 digits are based on a formula using the first 7 numbers.

Please note that this test may not work for new VAT registration numbers. As an alternative to the VAT number checker test below you can use the EU VAT Checker website which can be used to check all VAT numbers within the EU.

VAT Number Checker Test

Step 1:

List the first 7 numbers of the VAT registration number vertically.

Step 2:

Next to the 1st number write the number 8, next to the 2nd write the number 7, 3rd number 6 and so on down to the 7th number write the number 2.

Step 3:

Multiply each line of numbers so that the 1st VAT number is multiplied by 8, the 2nd VAT number is multiplied by 7 and so on.

Step 4:

Sum all of the multiplied answers.

Step 5:

Deduct 97 from the answer in step 4. Continue deducting 97 from your answer until the number is negative.

Step 6:

The negative number should be the last 2 digits of the VAT registration number.

Check VAT Number Example

To check that the VAT number 314 1592 83 is valid we will follow the steps above.

Steps 1, 2 and 3:

3 x 8 = 24
1 x 7 = 7
4 x 6 = 24
1 x 5 = 5
5 x 4 = 20
9 x 3 = 27
2 x 2 = 4

Step 4:

24 + 7 + 24 + 5 + 20 + 27 + 4 = 111

Step 5:

111 - 97 = 14, this is not a negative number, therefore continue deducting 97
14 - 97 = - 83, this is negative

Step 6:

As 83 is the last 2 digits of the VAT registration number. This seems to be a valid VAT number. As an additional check please read our EU VAT Checker webpage.