Stage 1: Agreement in Principle
An Agreement in Principle (AIP), also called a Decision in Principle or Mortgage in Principle, is a conditional indication from a lender of how much they would be willing to lend, based on a basic assessment of your income, expenditure, and credit profile. It is not a formal offer and is not legally binding.
Most AIPs involve a soft credit check (which does not affect your credit score) or a hard check (which does). Ask which type will be conducted before you apply. An AIP is typically valid for 60–90 days and is required by most sellers and agents before they will accept an offer seriously.
Stage 2: Full Mortgage Application
Once your offer on a property is accepted, you submit a full mortgage application to your chosen lender. This involves providing detailed documentation: proof of identity, proof of address, three to six months' payslips, P60, three months' bank statements, employer reference if self-employed (two years' accounts and tax calculations via HMRC SA302), and details of any existing debts or financial commitments.
Lenders assess your application against two criteria: affordability (can you service the debt given your income and outgoings?) and creditworthiness (does your credit history indicate you will repay as agreed?). Most lenders use automated scoring systems for the initial assessment, with manual underwriting for cases that fall outside standard parameters.
Stage 3: Mortgage Valuation
Your lender will instruct a valuation of the property you are buying. This is to confirm the property provides adequate security for the loan — it is not the same as a building survey and does not check for structural defects or maintenance issues. It simply confirms the property is worth approximately what you are paying for it.
Valuation fees range from zero (many lenders offer free valuations as part of their mortgage product) to £300–£1,500 depending on the property value. The result is either a confirmed valuation at or near the purchase price, a down-valuation (the surveyor values it lower than the agreed price), or a request for further information.
Stage 4: Underwriting
After valuation, your application goes to the underwriting team. They verify all the documents you have provided and may raise additional queries — known as conditions. Common conditions include: explanation of a credit blip, clarification of a large deposit or transfer in your bank statements (evidence of source of funds), confirmation of employment, or additional income evidence.
Respond to underwriting conditions promptly and fully. Delays in responding are one of the most common causes of mortgage offers taking longer than expected. Keep your bank account clean during this period — avoid large cash deposits, unusual transfers, or missed direct debits that might raise questions.
Stage 5: Formal Mortgage Offer
Once underwriting is satisfied and the valuation is confirmed, the lender issues a formal mortgage offer. This is a legally binding commitment to lend, subject to the conditions in the offer (the property completing, your circumstances not changing materially). The offer is sent to both you and your solicitor.
Mortgage offers are typically valid for 3–6 months. If your transaction is taking longer, contact your lender to request an extension before the offer expires. Most lenders will extend once for free. Check all details in the offer carefully: loan amount, term, interest rate, and monthly payment.
Frequently Asked Questions
How long does a mortgage application take from submission to offer? Typically 2–6 weeks from full application to formal offer, though some lenders are faster. Delays usually occur at the underwriting stage when additional information is requested. Using a mortgage broker who knows which lenders are processing quickly can help.
Does a mortgage application affect my credit score? The full application involves a hard credit search which will appear on your credit file. Multiple hard searches in a short period can reduce your score temporarily. Getting an AIP is a safer first step as some lenders conduct only a soft search at that stage.
Can I switch lenders after my offer is accepted? Yes, but it restarts the application process and could delay your transaction by 4–8 weeks. Only switch if you have a strong reason (significantly better rate, your original lender's offer is expiring) and discuss timing with your solicitor first.
What documents do I need for a self-employed mortgage application? Typically two to three years of accounts (usually prepared by an accountant), the most recent two years of HMRC SA302 tax calculations and tax year overviews, and three to six months of business and personal bank statements. Some lenders are more flexible for self-employed applicants than others.
What happens if my mortgage offer expires before completion? Contact your lender immediately to request an extension. Most will extend once for free for a further 3 months. If your circumstances have changed materially since the original offer, the lender may reassess and the offer may be revised.
Can I change my mortgage after exchange but before completion? Changing your mortgage product after exchange is risky — if the new application is refused, you are legally bound to complete but cannot fund the purchase. Only consider this in exceptional circumstances and with your solicitor's awareness.
Key Takeaways
- ✓Get an Agreement in Principle before viewing properties — it establishes your budget and makes you a credible buyer
- ✓The full application requires detailed income, employment, and bank account documentation — gather these in advance
- ✓A down-valuation creates a funding gap that must be resolved before the lender will proceed
- ✓Respond to underwriting conditions promptly — delays here extend the timeline for everyone in the chain
- ✓Check the mortgage offer carefully for accuracy and note the expiry date