Αλγόριθμος ορθότητας ΑΦΜ Greek Tax Registration Number Validation (AFM)

afm-validator.js

// Greek Tax Registration Number Validation (AFM)
// Αλγόριθμος ορθότητας ΑΦΜ
function validateAFM(afm) {
    if (!afm.match(/^\d{9}$/) || afm == '000000000')
        return false;

    var m = 1, sum = 0;
    for (var i = 7; i >= 0; i--) {
        m *= 2;
        sum += afm.charAt(i) * m;
    }

    return sum % 11 % 10 == afm.charAt(8);
}