The 14 calendar days between offer acceptance and arras signing are the highest-leverage period of the entire Marbella property transaction. In these days the buyer's lawyer retrieves and reviews approximately eight documents that collectively define the legal, fiscal, and operational reality of the property. What the stack reveals shapes whether the arras moves at the negotiated price, moves at a reduced price after renegotiation, or does not move at all because the property is structurally unfit for purchase.
A buyer who accepts a contrato de reserva that compresses the due-diligence window to under 10 days, or who waives any of the eight checks, is gambling. A buyer who insists on the full 14 days and the full stack — and who walks away when the stack surfaces material issues the seller will not address — does not lose deals; the buyer wins by avoiding the deals that should not close.
This article walks through the complete pre-arras due-diligence stack as it is operated by competent Marbella conveyancing firms in 2026 — the eight document categories, what each tells you, what each costs, the realistic timeline, and the findings that should kill a deal versus negotiate price reductions.
The standard Marbella transaction sequence is: written offer (day 0) → seller acceptance (day 1-3) → contrato de reserva signed and reservation deposit paid (day 5-10) → 14-21 day due-diligence window → arras signing and 10% deposit paid (day 21-35) → 60-90 day window to escritura → escritura signing and balance paid.
The 14-21 day window between contrato de reserva and arras is the structural moment for due diligence because: the property is off-market (the seller has committed not to entertain competing offers), the buyer has paid only a relatively small reservation deposit at risk, and the arras is the next document — and arras carries the 10% binding deposit that materially changes the buyer's exposure.
Due diligence findings during this window translate to: (a) confirmation that the deal can proceed at the agreed price; (b) renegotiation based on documented issues, with the seller typically accepting price reductions for issues the buyer evidences; or (c) buyer withdrawal with reservation deposit forfeit (the small €6K-€30K cost of avoiding the much larger arras commitment on a problematic property).
The 14-day window is operationally achievable because the eight document streams run in parallel rather than serially. Competent conveyancing firms execute the stack in 10-14 days routinely.
For the upstream offer-letter mechanics see offer letter mechanics article; for the reservation contract distinction see arras vs reservation article.