How to Finance an Auction Property: The 28-Day Timeline Step by Step

How does buying at auction actually work?

At a traditional (unconditional) auction the fall of the hammer is exchange of contracts. You are legally bound to buy at that price and the vendor is bound to sell. You pay a deposit, normally 10% of the purchase price, there and then, plus the auctioneer's buyer's fee. Completion is set by the contract, usually 28 days later, occasionally 20 or 14 for a motivated seller, and the date is fixed. If you do not complete, you lose the deposit and can be sued for the vendor's losses on a resale.

Every lot comes with a legal pack (title, searches, special conditions, leases, planning) published before the sale. Everything you need to know about the risk is in there, which is why the real work on an auction purchase happens before the day, not after.

Why does a mortgage rarely work for an auction purchase?

Two reasons. The first is time: a mortgage application typically takes four to eight weeks from application to offer, then more for legals, and lenders will not commit to a 28-day date. The second is the property: auction lots are often there precisely because they are hard to mortgage. No functioning kitchen or bathroom, structural issues, a short lease, sitting tenants, non-standard construction, mixed use, or simply a vendor who wants certainty.

A bridging lender has neither problem. It lends against the property's value and your exit, can complete in 5–10 working days on a clean case, and will take on lots in any condition provided the figures work. You then refinance onto a mortgage or sell once the property is in a lendable state. That is what auction bridging loans are built for.

Before the auction: what to do in the two weeks before the sale

1. Day −14: shortlist lots and read the legal packs. Download the pack for every lot you might bid on. Look for the completion period in the special conditions, any seller's additional fees, title restrictions, lease length, tenancies and planning history. Send the pack to your solicitor; a legal pack review costs £200–£500 and is the best money you will spend.
2. Day −10: get indicative bridging terms. Give your broker the lot, guide price, your maximum bid, your deposit and your exit. Indicative terms come back in 24 hours with no credit search. This tells you your true maximum bid: the amount you can fund, not the amount you hope the lender will fund.
3. Day −7: decision in principle on the specific lot. The lender runs a soft search and confirms it will lend on that property type at that LTV. Ask which valuation route they will use. On a standard house or flat, a desktop or AVM can be instructed the day after the auction, or in some cases before it.
4. Day −5: view the property and check the comparables. Auction lots are sold as seen. If the lender will rely on a desktop valuation, you are the only person who will have looked inside, so look properly.
5. Day −3: confirm your deposit funds and ID. The auctioneer needs cleared funds on the day and your anti-money-laundering checks done in advance. Register to bid.
6. Day −1: set the walk-away price. Based on the indicative terms, your cash, the refurbishment budget and the exit value. Write it down. Rooms are designed to move it.

Auction day: what happens when the hammer falls?

If you are the winning bidder you sign the memorandum of sale, pay the 10% deposit and the buyer's fee (commonly £1,000–£2,000 plus VAT, or a percentage on some sales), and you have exchanged. Tell your broker and solicitor immediately, ideally from the room. The lender's clock now starts: the full application goes in the same day, the valuation is instructed and the lender's solicitor is sent the legal pack.

Many lots do not sell in the room. If a lot you wanted is unsold, you can usually buy it afterwards at or near the reserve on the same contract terms, and the same timeline applies from the moment you exchange.

After the hammer: the 28 days, day by day

Typical timeline for a residential lot with a bridging lender in November 2026. Clean cases complete well inside this; the table shows where the margin goes.

The single biggest determinant of whether 28 days is comfortable or frightening is the solicitor. Use one who completes bridging transactions regularly, is on the lender's panel or accepts their requirements, and will take indemnity insurance in place of full searches where the lender allows it.

What changes with a modern method (conditional) auction?

Online "modern method" auctions work differently. The winning bid pays a non-refundable reservation fee (typically 3–5% of the price, often with a minimum of £5,000–£6,000 plus VAT) rather than a deposit, and then has 56 days to exchange and complete. The reservation fee is usually in addition to the price and does not count towards it.

The extra time makes a mortgage possible in principle, and some buyers use one. In practice many still bridge, because the fee is lost if the mortgage falls through and 56 days is tight for a mortgage on anything unusual. The finance steps above are the same; you simply have twice the time, which is also twice the time for something to go wrong with a mortgage lender.

What does auction finance cost?

• Interest: from around 0.61% a month on residential lots at low LTV, more typically 0.75–1.0% at 65–75% LTV. Usually retained from the advance, so there are no monthly payments.
• Arrangement fee: typically 2% of the loan.
• Valuation: £0 for an AVM, £150–£400 for a desktop, £500–£2,000+ for an inspection.
• Legal fees: your solicitor and the lender's, usually £1,500–£3,000 combined on a straightforward lot.
• Auction costs: the buyer's fee, and any seller's costs passed on in the special conditions.
• Exit costs: there is normally no early repayment charge after a minimum term of one to three months, so a fast refinance costs little extra.

On leverage, lenders will go to around 75–80% of value on a straightforward residential lot, higher if you are buying to refurbish (up to 90% of purchase with works funded in stages) and, where you are buying well below market value, some will lend against the true value and fund up to 100% of the price. The product page sets out the current limits.

A worked example: a three-bed terrace bought at auction to refurbish and refinance

A first-time investor wins a tired three-bedroom terrace for £165,000 (guide £150,000). It has no kitchen, so no mortgage lender will touch it. Comparables for refurbished houses on the street are £230,000. Refurbishment budget is £25,000 over three months, then refinance onto a buy-to-let mortgage.

The remortgage repaid the bridge and returned most of the investor's cash. Total bridging cost was around £11,300 plus legals. Figures are illustrative and rounded.

What happens if you can't complete in time?

The auction contract will usually allow the vendor to serve a notice to complete, giving you a further 10 working days with daily interest at a contractual rate (often 4–5% above base) on the balance. If you still do not complete, the vendor can rescind, keep your deposit, resell the property and claim any shortfall and costs from you. It is as serious as it sounds, and it is why finance is arranged before the bid.

What are the common mistakes with auction finance?