Invoicing and IVA

Key facts

The retention: why your invoice pays out less than its total

When a professional invoices a Spanish business client, the invoice shows an IRPF retention — a slice of the fee the client does not pay to you but withholds and pays to the Agencia Tributaria as an advance on your income tax. The standard rate is 15%. New professionals apply a reduced 7% in the year they start and the two following years, provided they carried out no professional activity in the year before starting.

Retention only appears when the client is a Spanish business or professional. Invoices to private individuals and to clients abroad carry no retention — which is why a freelancer whose only client is a foreign company (a common profile after working remotely from Spain for a foreign employer turns into contracting) may never see one on their own invoices.

The IVA calendar: Modelo 303 and Modelo 390

IVA collected on your invoices is not yours — you hold it until the quarterly return, Modelo 303, hands it to the Agencia Tributaria. The filing windows:

1. Q1 (January–March): 1–20 April
2. Q2 (April–June): 1–20 July
3. Q3 (July–September): 1–20 October
4. Q4 (October–December): 1–30 January — ten extra days

January doubles up: alongside the Q4 return, the annual summary Modelo 390 is also due by 30 January. It recapitulates the year’s four quarters; nothing new is paid with it, but skipping it is a sanctionable omission.

Invoicing EU clients: ROI, VIES and Modelo 349

Invoices to business clients in other EU countries normally go out without Spanish IVA: under the reverse charge, the client self-accounts for VAT in their own country. But the mechanism only works if both sides are registered intra-community operators:

1. Register in the ROI (Registro de Operadores Intracomunitarios) by ticking casilla 582 on Modelo 036, with the date of your first intra-EU operation in casilla 584. Since 3 February 2025 the simplified Modelo 037 no longer exists — every census filing goes through 036.
2. Registration turns your NIF into a NIF-IVA with the ES prefix, visible to your clients in VIES, the EU’s VAT-number validation system. Until you appear there, EU clients cannot reverse-charge your invoices.
3. Report the operations in Modelo 349, the recapitulative return. It is purely informative — no tax is paid with it — but it is how AEAT cross-checks the reverse charge.

Clients outside the EU are a different regime again: no VIES, no 349 — the invoice is simply outside the scope of Spanish IVA in most service cases.

Verifactu: the invoicing-software mandate — with the real dates

Verifactu (RD 1007/2023) requires invoicing software to produce tamper-evident, traceable billing records — either sending them to AEAT in real time or keeping signed, chained records locally. The compliance deadlines are the single most misreported fact in this topic, because they have been postponed twice — first by RD 254/2025, then by RDL 15/2025 of 2 December 2025. The law as it stands:

• Corporate income tax payers (Impuesto sobre Sociedades): 1 January 2027
• Everyone else, including autónomos: 1 July 2027

Not 2026 — and not 2028; articles at the top of the search results still quote the earlier calendar. One date has already arrived: since 29 July 2025 developers may only sell adapted, Verifactu-capable systems, so compliant products exist well before you are obliged to use one.

A separate thing entirely: mandatory B2B electronic invoicing under Ley 18/2022 (art. 12). It is a different regime whose deadlines depend on an implementing reglamento not finally deployed as of August 2026 — no date attached to it today is definitive. Any article that merges it with Verifactu into one "e-invoicing deadline" is mixing two laws.

Delegating the cycle

None of the above is conceptually hard, but it recurs every quarter, and the penalty for a missed window is automatic. This calendar — 303, 390, 349, retention reconciliation — is precisely the workload behind the monthly-retainer model described in working with a gestor.

⚠ Scams to avoid

• ✗ "Our software is already AEAT-approved for Verifactu — switch today or face fines." There is nothing to be fined for before the deadlines: companies are bound from 1 January 2027 and autónomos from 1 July 2027 (RDL 15/2025). Vendors compressing that timeline are selling urgency, not compliance.
• ✗ "Verifactu applies from 2026." Out of date twice over — the calendar was moved by RD 254/2025 and again by RDL 15/2025. Check the BOE, not a blog’s cached headline.
• ✗ "We’ll activate your VIES number — special procedure, paid service." ROI registration is a tick in casilla 582 of Modelo 036. A third party may file it for you as a convenience, but there is no special activation channel to sell.