Spanish VAT Number Validation

Spanish VAT numbers are the most complex in the EU, with different formats and validation rules depending on whether the entity is a legal entity (CIF), Spanish citizen (DNI), or foreigner (NIE).

Format Overview

Regex Pattern

^ES[A-Z0-9][0-9]{7}[A-Z0-9]$

Types of Spanish VAT Numbers

CIF (Starts with A-H, J, N, P-W) - Legal Entities

CIF validation uses weighted sums with doubling. The same checksum value can be represented as a numeric control digit or an equivalent control letter:

def validate_cif(number):
    control_letters = "JABCDEFGHI"

    total = 0
    for i, digit in enumerate(number[1:8]):
        value = int(digit)
        if i % 2 == 0:
            value *= 2
            if value > 9:
                value = value // 10 + value % 10
        total += value

    control_digit = (10 - (total % 10)) % 10
    control_letter = control_letters[control_digit]
    first = number[0]
    check = number[8]

    if first in "KLM":
        return check == control_letter
    if first in "ABCDEFGHJNPQRSUVW":
        if check.isdigit():
            return int(check) == control_digit
        return check == control_letter
    return False

• Double alternating digits (positions 1, 3, 5, 7 of the 7-digit body)
• If a doubled value is > 9, sum its digits before adding
• Control digit = (10 - (total % 10)) % 10, control letter = JABCDEFGHI[digit]
• K, L, M: Always letter check
• A-H, J, N, P-W: We recommend accepting either the numeric control digit or the equivalent control letter. Official documentation has conflicting information on which is required for each organization type.

DNI (Starts with digit) - Spanish Citizens

def validate_dni(number):
    letters = "TRWAGMYFPDXBNJZSQVHLCKE"
    digits = number[:8]
    check = number[8]
    return letters[int(digits) % 23] == check

NIE (Starts with X, Y, Z) - Foreign Residents

def validate_nie(number):
    letters = "TRWAGMYFPDXBNJZSQVHLCKE"
    prefix = {"X": "0", "Y": "1", "Z": "2"}
    digits = prefix[number[0]] + number[1:8]
    check = number[8]
    return letters[int(digits) % 23] == check

Important Notes

• For CIF-style numbers, accept either the numeric control digit or equivalent control letter because official documentation conflicts on which is required.
• Some Spanish VAT numbers are for domestic use only and won't appear in EU-wide systems. Use VatDB to check if a Spanish VAT number is active for intra-EU commerce.