Guided workflow for preparing and filing a Spanish IVA (VAT) self-assessment via Modelo 303, including reverse-charge classification, intra-EU recapitulative Modelo 349, and annual Modelo 390 summary. Covers quarterly and monthly filers, SII obligations, and casilla mapping for all transaction types.
Confirm the client is registered for IVA with AEAT, establish the filing period and frequency (quarterly vs monthly), verify territorial scope (peninsular Spain or Balearic Islands — not Canary Islands, Ceuta, or Melilla), and collect the NIF-IVA. Identify whether the client is SII-obliged (turnover > EUR 6,010,121.04 or registered in REDEME) or on the simplified modules regime (regimen simplificado).
Gather the complete invoice register (libro registro de facturas emitidas y recibidas) or, at minimum, the bank statement for the period. Collect sales invoices (facturas emitidas) for intra-EU B2B services and zero-rated exports, and purchase invoices (facturas recibidas) for any input IVA claim above EUR 300. Retrieve the prior-period Modelo 303 to carry forward any casilla 67 credit.
Classify every transaction by rate, direction, and territorial origin using the AEAT casilla framework. Apply the supplier pattern library for deterministic cases (utilities at 21%, RENFE at 10%, bank charges exempt under Art. 20.Uno.18 LIVA). Apply reverse-charge rules for EU services (casilla 17/18 + 32/33) and non-EU services (casilla 19/20 + 36/37). Apply the 50% vehicle presumption under Art. 95.Tres.2 LIVA and the bienes de inversion threshold of EUR 3,005.06. Flag ambiguous lines for Tier 2 structured questions.
Populate Modelo 303 from the classified transaction register. Compute output IVA totals by rate (casillas 01–06 for domestic sales; 15–20 for acquisitions/reverse charge), input IVA totals (casillas 28–39), prorrata percentage if applicable, and the net result in casilla 64. Apply the casilla 67 credit from the prior period. Determine whether the result is a payment (ingreso), a carry-forward credit, or a refund request (devolucion). Validate that intra-EU totals in casillas 15–18 reconcile with the Modelo 349 draft.
Submit Modelo 303 (and Modelo 349 if required) through the Sede Electronica of AEAT using the client's Cl@ve PIN, certificado digital, or DNI electronico. Confirm the presentation locator (justificante de presentacion) and any direct-debit mandate (domiciliacion bancaria) for payment. At year-end (Q4 filing), prepare and file Modelo 390, the annual IVA summary — noting that SII-obliged entities are exempt from Modelo 390.
Run this workflow in your AI agent
Install the MCP connector once — your agent loads the right skills, works through each phase, and routes to a licensed Spain accountant for review.
spain-vat-return
Use this skill whenever asked to prepare, review, or classify transactions for a Spanish V
es-vat-return
Redirect — consolidated into spain-vat-return.md in this directory.
spain-einvoice
Use this skill whenever asked about Spanish e-invoicing, factura electrónica Spain, FACe,