The Mortgage Application Process, Step by Step

Where Are You in the Process?

Six stages sit between deciding to buy and picking up the keys. Most of the time in that process is not spent waiting on a mortgage decision. It is spent on searches, legal checks and a chain that moves at its own pace. The mortgage side, done properly, is the part most within your control.

This guide walks through what actually happens at each stage in 2026, roughly how long it takes, what it costs, and where things commonly slow down. If you already know which stage you are at, the headings below let you jump straight to it.

Stage 1 – Agreement in Principle

An Agreement in Principle, sometimes called a Decision in Principle, is a lender’s early statement of how much they would consider lending you, based on a soft credit check and the income and outgoings you declare. Most lenders return one within minutes online, or same-day through a broker checking multiple lenders at once. It is not a guarantee. Full underwriting still has to confirm it.

An AIP typically stays valid for 60 to 90 days, though some lenders offer as little as 30. If your property search runs longer, you can usually renew it. Getting one before you view properties seriously matters for two reasons: it tells you what you can realistically spend, and estate agents take offers more seriously when finance is already lined up.

For a fuller picture of what a lender is actually calculating at this stage, see our guide on how much you can borrow.

Stage 2 – Gathering Your Documents

Once you have an AIP, the next stage is assembling what a lender will ask for at full application. Doing this before you need it is the single biggest lever you have over how fast the rest of the process moves.

Most lenders want:

Proof of identity – passport or driving licence.
Proof of income – three months of payslips, or two to three years of accounts and SA302s if you are self-employed.
Bank statements – usually the last three months, sometimes six.
Proof of deposit – a clear paper trail showing where the money came from.
Address history – your last three years, for the credit check.

Missing or inconsistent documents are one of the most common causes of delay at underwriting. A wrong address, a gap in bank statements, or a deposit that cannot be clearly traced all generate follow-up questions that add days or weeks. Gathering everything before you apply, rather than after a lender asks, is what keeps a straightforward case straightforward.

Stage 3 – Full Application and Underwriting

With an accepted offer on a property, the full mortgage application goes in. This is where the AIP’s soft check becomes a hard credit search and a detailed review of your finances.

For a standard employed applicant with a complete application, most lenders issue a formal mortgage offer within two to four weeks. Self-employed cases usually add one to two weeks, since accounts and SA302s need manual review rather than automated checking. Busy periods or specialist lenders can push this to five to eight weeks.

Underwriters are not just confirming your income. They are running the affordability model – checking committed outgoings, credit history and bank statement behaviour, then stress-testing the mortgage at a rate above the one you will actually pay. This is where an AIP and a final offer can diverge, and it is worth understanding before you get to this stage. Our guide on how lenders calculate affordability covers exactly what gets checked and why the final figure sometimes comes in lower than expected.

Stage 4 – Valuation and Survey

Once the application is with underwriting, the lender arranges a valuation to confirm the property is worth what you are paying. This protects the lender’s security, not you – it is not a survey of the property’s condition.

A basic valuation typically costs up to £300 and takes one to two weeks, sometimes faster if the lender uses an automated desktop valuation rather than a physical inspection. Most buyers also commission their own survey alongside it: a homebuyer’s report runs roughly £300 to £600, while a full building survey for an older or unusual property can run £400 to £1,500 or more.

If the valuation comes back below the agreed price, the lender will only lend against the lower figure. That gap has to be closed with a bigger deposit, a renegotiated price, or in some cases the purchase falls through. It is one of the more disruptive things that can happen at this stage, and worth budgeting a small buffer against.

Stage 5 – Mortgage Offer

Once underwriting and valuation both check out, the lender issues a formal mortgage offer. Unlike the AIP, this is a binding commitment on specific terms – loan amount, rate, and any conditions attached.

Offers are usually valid for three to six months. If your conveyancing runs longer than that, which is common, you can normally request an extension or the lender will re-verify your income before confirming. Your solicitor reviews the offer alongside the legal work already underway, checking the terms match what you agreed and flagging anything unusual.

Stage 6 – Legal Work, Exchange and Completion

The legal side runs in parallel with the mortgage stages above it, and is usually the slower half of the whole process. Your conveyancer conducts property searches, reviews the title, raises enquiries with the seller’s solicitor, and prepares for exchange. Searches alone typically take two to six weeks.

Conveyancing fees usually run £1,000 to £1,800, plus search fees of roughly £250 to £450 and a Land Registry fee that scales with property value. Stamp Duty Land Tax is calculated on the purchase price in bands: first-time buyers currently pay nothing up to £300,000, then 5% on the portion between £300,001 and £500,000. Above £500,000, first-time buyer relief no longer applies and standard rates are charged in full. A non-first-time buyer pays 0% on the first £125,000, 2% on the next £125,000, and 5% above that up to £675,000.

Worked example: a first-time buyer purchasing a £280,000 property with a 10% deposit pays no Stamp Duty at all, since the full price sits under the £300,000 threshold. Their deposit is £28,000, leaving a £252,000 loan. Conveyancing and search fees together typically add a further £1,300 to £2,400 in cash needed before completion, on top of the deposit itself.

Exchange of contracts is the point both sides become legally committed and a completion date is fixed. Completion itself, when funds transfer and you collect the keys, usually follows one to four weeks after exchange.

What Actually Causes Delays

Most delays trace back to a handful of causes, and most are avoidable with earlier preparation.

Slow document turnaround from the applicant is the single most common one – every day spent finding a missing bank statement is a day added to the timeline. Down valuations, covered above, are the second most disruptive since they can unwind an agreed price. Chain delays, where your purchase depends on someone else’s sale completing, sit largely outside your control but are worth discussing with your broker early. And credit issues surfacing at full application that were not visible at AIP stage – a recent missed payment, an unexpected CCJ – can require a change of lender partway through.

If a full application does not go the way you expected, our guide on why mortgages get declined covers the most common reasons and what a next application should look like.

What This Costs in Total

Beyond the deposit itself, most buyers should budget for:

Stamp Duty – £0 to several thousand pounds depending on price and buyer status.
Conveyancing and search fees – roughly £1,300 to £2,250 combined.
Survey – £300 to £1,500 depending on type and property age.
Mortgage valuation fee – up to £300, sometimes waived.
Mortgage arrangement fee – up to £1,500 on some deals, though fee-free options exist.

For a full breakdown of what a specific deposit level costs month to month, our mortgage rates page sets out current ranges by loan-to-value band.

Frequently Asked Questions

Final Thoughts

Understanding the stages before you start makes the whole process feel far less unpredictable. The mortgage side – Agreement in Principle, documents, underwriting, offer – is usually the two to four weeks most within your control. The legal work running alongside it is typically the longer half, and largely outside your hands once instructed.

If you would like a clearer idea of what you can borrow, what a lender will actually approve, or simply where to start, get in touch and we will walk you through it.

UK Mortgage Broker is a whole-of-market broker helping clients throughout the UK and globally to secure funding on UK property. We are directly authorised and regulated by the Financial Conduct Authority. Your home may be repossessed if you do not keep up repayments on your mortgage.

Call: +44 1628 969 500
Email: info@uk-mortgagebroker.co.uk

Related Pages

• Can I Get a Mortgage? – eligibility criteria and what lenders assess before approving an application
• First-Time Buyer Mortgage UK – deposit levels, borrowing limits and the full application process
• Documents You Need for a Mortgage Application – the full checklist before you apply
• Mortgage Declined After Agreement in Principle – what changes between AIP and full application
• Types of Mortgage UK – fixed, tracker, interest-only and repayment options compared