contix herramientas

Compute the taxable base, VAT (IVA) amount, optional recargo de equivalencia and optional IRPF withholding from an amount. By default `importe` is the taxable base (sin IVA). With incluye_iva=true, `importe` is the TOTAL with VAT already included and the base is derived backwards (quitar IVA / reverse VAT). It only applies the rates it is given: it does NOT decide which VAT or IRPF rate applies to

Two modes in one input. If `valor` is only 1-8 digits, computes the DNI check letter and returns the full 8-digit-plus-letter DNI (digits are left-padded with zeros). If `valor` is a full document, validates its check character: DNI (8 digits + letter), NIE (X/Y/Z + 7 digits + letter) or CIF (entity letter + 7 digits + check digit or letter, with the entity type per Orden EHA/451/2008). Tolerates

Check whether an IBAN is well formed: country length (SWIFT IBAN registry) and ISO 13616 check digits. For Spanish IBANs also the two account check digits (DC) and the bank (entidad) with its BIC from the Banco de España registry. A 20-digit Spanish account number (CCC) is converted to its IBAN. Pure arithmetic: it does NOT confirm that the account exists or who owns it.

Look up an EU VAT number in the European Commission's VIES registry. Returns what the registry says: whether the number exists and, where the member state publishes it, the name and address. It draws NO tax conclusion. VIES is often down; that is reported as disponible=false, which is NOT the same as an invalid number.

Add up the boxes (casillas) of the Spanish quarterly VAT return Modelo 303 with the formulas printed on the official AEAT form: 27, 45, 46, 64, 66, 87, 69 and 71. Input are the tax amounts (cuotas) per box, e.g. {"09": 17430, "29": 9870}. It only sums what it is given: it does not decide which rate or deduction applies and it is not a tax return.

Deadlines from the published Spanish rules: Veri*factu (RD 1007/2023, dates of RD-ley 15/2025) and mandatory B2B e-invoicing (RD 238/2026, counted from the ministerial order, provisional while the order is a draft). Information about the rules, not advice.