How a BOE auction works

Since Ley 19/2015, virtually every public auction in Spain runs on the same technical platform.

Before 2015, every court, notary or tax authority held auctions physically, each in its own way and at its own pace. Since then, the technical process — registration, deposit payment, bidding, closing — runs through exactly the same system for every type of auction: the Portal de Subastas (subastas.boe.es), managed by the Agencia Estatal Boletín Oficial del Estado. What does differ per type is who orders the auction and under which legal regime — that is the subject of §4.

A BOE auction always originates from one of three families:

This document works out the judicial route in detail — by far the largest share of supply, and the most extensively regulated by law (LEC, Ley 1/2000, amended by Ley Orgánica 1/2025, in force since 3 April 2025). §4 places the other two families alongside it.

Three phases: appraisal & announcement, the bidding itself, and the award — the last being where the statutory floors really come into play.

2.1 — Before the auction

Appraisal (valor de subasta): in a mortgage foreclosure, usually the amount already stated in the mortgage deed itself (art. 682 LEC); otherwise the court appoints an independent appraiser. The announcement (edicto) is published on the portal with the appraisal value, known encumbrances, occupancy status where known, and the opening date.

2.2 — The bidding process

There is no statutory minimum bid during the bidding itself — the auction can open at any amount, even well below the appraisal. That floor is only tested after closing, at the award stage. A low running bid during the auction therefore says nothing about whether that auction will actually result in an award.

2.3 — The award process

After closing, the LAJ tests the best bid against the statutory threshold (art. 670 LEC, after LO 1/2025):

"No se aprobará el remate de la vivienda [habitual] por cantidad inferior al 70 por 100 de su valor de subasta, salvo que se haga por la cantidad que se le deba al ejecutante" — art. 670 LEC

No bids at all (subasta desierta, art. 671 LEC): the basic rule is that the LAJ, at the request of the debtor, lifts the seizure. There is also an alternative path: the debtor — themselves, or on the creditor's proposal — can designate a party willing to take over the property for at least 50% of the auction value, or 40% if that is enough to fully satisfy the claim.

"Si en la subasta no hubiere ningún postor, el letrado o letrada de la Administración de Justicia, a instancia del ejecutado, procederá al alzamiento del embargo" — art. 671 LEC

Formally, then, it is the debtor who is the designating party, not the creditor awarding the property "to themselves" — in practice, the designated transferee is often the creditor itself, precisely because it has the greatest interest in it. An empty auction therefore does not automatically release the property from seizure.

Cesión de remate (assignment of the winning bid to a third party): the enforcing creditor and subsequent creditors retain this right without having to make a prior declaration — via a request signed by both parties, within a fixed period after closing and payment. Any surplus above the claim must be deposited into the court's account within 10 days, or the auction fails after all.

Payment & non-payment: the remainder (bid minus deposit) is due within 20 calendar days (was 40) — the period runs automatically from publication, without separate notice. Non-payment costs the entire deposit (now 20% instead of 5%, min. €1,000) and is called quiebra de la subasta: the auction restarts, with the costs charged to the defaulting bidder.

The decreto de adjudicación is the title for registration in the Registro de la Propiedad — not a notarial deed, relevant for §3.2. Only in a judicial auction can the enforcement judge subsequently order a lanzamiento (forced eviction); notarial and administrative auctions lack that title.

Ten cost items, one tax peculiarity for public auctions, and a fully worked example.

3.1 — The tax base: usually NOT the winning bid

Since the reform of art. 10 TRLITPAJD (Ley 11/2021), the main rule for real-estate transactions is the highest of three values: purchase price, cadastral reference value, or declared value. The Reglamento also contains a separate rule, favourable at first sight, for public auctions (art. 39 RITPAJD): there, the acquisition price — the winning bid — would apply as the tax base.

Two binding DGT rulings (V0453-22 and V1512-22, confirmed by, among others, Cuatrecasas) show that this is not the practice actually applied:

"La base imponible de TPO será [...] el valor de referencia del inmueble [...] y no el valor de adquisición mediante subasta judicial" — DGT

The law itself (art. 10.2 TRLITPAJD) takes precedence over the regulatory auction exception as soon as a cadastral reference value exists for the property — and that has been the case for virtually every registered Spanish property since 2022. The special rule therefore, in practice, only applies to properties without a reference value. For all other cases: tax base = the highest of (cadastral reference value, winning bid, declared value) — exactly the same rule as for an ordinary sale.

3.2 — Notary and registry fees: the official scales

Both fees are set by law as a regressive scale: each bracket of the value carries its own rate, added together to reach the total.

Notaries may grant up to 10% discount; for home sales, a statutory discount of 5% also applies. Both fees are subject to 21% VAT (an ordinary, VAT-liable service, separate from the ITP/VAT regime of the real-estate transaction itself); the registry fee is furthermore capped at €2,181.67 per registration.

3.3 — Worked example: highest bid €100,000, home, judicial auction

The platform covers all of Spain — this is therefore explicitly one illustration of the calculation method, not the only applicable region. Catalonië was chosen as the example because the platform was first tested there; simply substitute the ITP rate from §4.1 for the region of a specific auction — the rest of the calculation (deposit, notary/registry scale) does not change per region.

The direct, virtually certain additional cost burden in this example comes to roughly 10.5% of the bid — before looking at encumbrances, arrears or the condition of the property, and assuming a cadastral reference value that is not above the bid. That is consistent with what specialised sources more broadly report for a second-hand purchase in Spain: typically 8–14%, strongly region-dependent. See §4.1 for the gran tenedor risk that can double this percentage.

3.4 — Encumbrances that are not costs, but do carry over

Not a new expense on completion day — an assumed obligation:

Builds on BOE_Veilingtypes_Referentie_v1.0.md §4 — here with the bidding, award and cost dimension alongside it.

Main risk per family: for judicial, the complexity of encumbrances/occupancy in older proceedings (median age 4 years, see BOE_CuentaExpediente...); for notarial, the absence of an eviction title; for tributaria, that old encumbrances remain without transfer of possession; for administrativa general, usually the cleanest profile, but small and irregular supply.

4.1 — ITP rates per region: all of Spain

Each autonomous region sets its own ITP rate and reductions. The platform (PROD) covers all of Spain, so the table below does too. The worked example in §3.3 uses Catalonië as an illustration of the calculation method; that same method is directly applicable to any other region by simply substituting the general rate below.

Standard TRLITPAJD regime — 16 of the 17 regions + Ceuta/Melilla:

Foral regimes — own tax system, not TRLITPAJD:

4.2 — VAT/AJD in JC insolvency auctions

ITP applies if the seller (at JC: the estate) is a private individual; VAT if the seller is a business/self-employed person. Specifically for JC, art. 84.Uno.2º.e Ley IVA provides for a reverse-charge mechanism (inversión del sujeto pasivo): for property transfers resulting from an insolvency proceeding, the VAT liability shifts to the acquiring business/self-employed person, to avoid collection risk from the insolvent seller.

Practical condition: VAT(+AJD) only comes into play at JC if (a) the debtor contributes the property in a business capacity (for an insolvent company this is the rule rather than the exception) and (b) the buyer is also a business/self-employed person. A private buyer simply pays ITP regardless of the reverse charge. And never ITP+AJD at the same time (art. 31.2 TRLITPAJD) — it is always one or the other.

• Financing conditions for the buyer themselves — a mortgage on an auctioned property is in practice harder to obtain than for an ordinary purchase.
• Precise ITP reductions per profile, exactly per region — §4.1 now covers all regions at the level of the general rate; the exact conditions/threshold amounts of each reduction have not been worked out per region.
• Tax treatment after purchase — transfer tax on a later resale, rental income tax.
• The exact frequency of VAT/AJD cases within JC insolvency auctions in our own dataset — §4.2 now explains the legal condition precisely, but the actual share has not been empirically tested (see §7).

• LEC (Ley 1/2000), consolidated, art. 647/670/671 (incl. full text of art. 671) — via Iberley, cross-checked via conceptosjuridicos.com/vLex
• Ley Orgánica 1/2025 — summaries via Iberley, De Trinidad y Asociados, Ashurst, RocaJunyent, Sepín, Uría Menéndez
• Ley 19/2015 — legal basis of the electronic auction portal
• Art. 9.1.e Ley de Propiedad Horizontal — liability for comunidad arrears
• IBI liability — Ley de Haciendas Locales, afección real; Idealista, De Trinidad y Asociados, Aticojurídico
• Art. 10 TRLITPAJD & art. 39 RITPAJD — DGT V0453-22 & V1512-22, in which the law takes precedence over the auction exception — Cuatrecasas, Lealtadis, Garrido, AEDAF, SuperContable
• Art. 20.Uno.22 & 84.Uno.2º.e Ley IVA, art. 31.2 TRLITPAJD — REFOR-Economistas, INEAF, Fiscal-Impuestos
• RD 1426/1989 & RD 1427/1989 — full scales via Notaría de Tarancón, Notaría de Tomares
• ITP Catalonië 2026 — Decreto-ley 5/2025, Rankia, ACFINAN, Agència Tributària de Catalunya
• ITP for the remaining 16 regions + Ceuta/Melilla, incl. Navarra/País Vasco (foral) — searched per region (Aragón, Madrid, Galicia, Andalucía, Valencia, Murcia, Castilla-La Mancha, Castilla y León) and cross-checked against a national overview (Hipotips) for the rest — InfoITP, GuíaFiscal, Hipotecas.me, BSCredit, ESECE, TaxDown, Interforo, Gibobs
• Cost overview for a subasta buyer — Subastech, CashStalker, Oportunalia, Auctia
• Builds on BOE_Veilingtypes_Referentie_v1.0.md and BOE_CuentaExpediente_Procedurecodes_v1.1.md

Five points from an earlier version of this document have since been checked against primary and highly authoritative sources (§2.3, §3.1–4.2) — two of them turned out to require a correction, not merely an addition. What remains is now more precisely delineated: