A mortgage in principle is one of the first practical steps in buying a home. It gives you an early indication of how much a lender might be willing to offer, helps you set a realistic budget, and shows estate agents you're a serious buyer.

This guide walks through how to get a mortgage in principle in 2026, including what you need to apply, how long it takes, how it might affect your credit score, and what to do once you have one. If you're just starting your home-buying journey or weighing up whether you're ready to apply, this is for you.

What is a mortgage in principle?

A mortgage in principle (AIP), also called an agreement in principle, decision in principle, or mortgage promise, is a conditional offer from a lender. It shows how much they might be willing to lend you based on basic information about your income, expenses, and credit history.

Think of it as a financial health check that can give you a clearer view of your potential budget before you start house hunting. It's not a binding mortgage offer, but it can show estate agents and sellers that you're a serious buyer with borrowing power in place.

Why getting an AIP can help

• It helps focus your property search on homes within a realistic budget range.

• It can strengthen your offers, as sellers may take you more seriously when you have lending arrangements in progress.

• It may help you spot potential issues early, before you find a home you love and risk disappointment.

• It lets you compare what different lenders might offer you.

AIP vs full mortgage offer: what's the difference?

An AIP is not the same as a mortgage offer. An AIP is based on the information you provide and a light-touch credit check. A full mortgage offer comes after a lender has verified your documents, run detailed affordability checks, and valued the property you want to buy. You need a full mortgage offer to actually buy a home, not just an AIP.

How to get a mortgage in principle: step-by-step

Most UK lenders offer AIPs online, by phone, or through a face-to-face appointment. The online route tends to be the fastest. Here's the general process:

• Check your credit report so you know where you stand before any lender does.

• Choose a lender directly or use a mortgage broker or comparison site to look at multiple options.

• Complete the application form with your personal and financial details.

• Consent to a credit check (this is usually a soft search that doesn't affect your credit score, but check before applying).

• Receive your decision, often within minutes for straightforward applications.

• Save or print your AIP certificate to use when house hunting.

Where to apply: bank, broker, or digital lender?

• Direct with a high street bank: Usually straightforward if you already bank with them, though you'll only see that lender's products.

• Through a mortgage broker: A broker can compare deals across multiple lenders and may have access to products that aren't available direct. Some brokers charge a fee, others are paid by the lender.

• Digital-only lenders: Often have fast online application processes and instant decisions for standard cases.

What you need to apply

• Personal details: Full name, address history for the past three years, date of birth, and contact information.

• Employment information: Job title, employer details, start date, and whether your role is permanent or temporary.

• Income figures: Annual salary, overtime, bonuses, and any other regular income such as rental or investment returns.

• Monthly outgoings: Existing loans, credit cards, childcare costs, and regular bills.

• Deposit amount: How much you have saved and available for your purchase.

You generally won't need to provide supporting documents at this stage, just accurate figures you can verify later if you proceed to a full application.

How long does it take to get a mortgage in principle?

Most online AIP applications can process within 10 to 30 minutes for straightforward cases. Phone applications typically take 30 to 60 minutes including the conversation time. Face-to-face appointments through mortgage advisers or bank branches usually complete within one working day, though you'll need to factor in booking time.

What can slow your application down

• Self-employed applicants often need manual review, which can extend timelines to 24-48 hours.

• Complex credit histories may require human assessment rather than automated decisions.

• High loan-to-income ratios can trigger additional checks that slow processing.

• Multiple income sources may need verification against lender criteria, adding to review time.

How long does an AIP last?

Most AIPs last 60 to 90 days from the issue date. Some lenders offer longer validity periods, while others may be shorter.

Your AIP automatically expires after this period, but renewal can be straightforward if your circumstances haven't changed. Contact your lender a week or two before expiry to extend or refresh your agreement. If your income, job, or financial situation has changed significantly, you'll usually need a fresh application rather than a simple renewal.

Does a mortgage in principle affect your credit score?

Most AIP applications use a soft credit search that doesn't appear on your credit file or affect your credit score. This lets lenders assess your creditworthiness without leaving a footprint.

However, some lenders perform hard credit searches for AIPs, which do appear on your credit file. These searches can temporarily lower your score if you make multiple applications quickly. Always check which type of search a lender uses before applying. Soft searches are generally preferable when you're shopping around.

Check your credit score before you apply

Before sending off an AIP application, it can help to know where you stand. You can check your credit score and report for free with ClearScore, which uses Equifax data in the UK. Seeing your report can help you spot any errors or issues you might want to resolve first.

Recent missed payments, high credit utilisation, or incorrect information could all affect your mortgage eligibility.

ClearScore also shows credit products matched to your profile through its eligibility checker, which can help you see which providers you may be eligible to consider, with no impact on your credit score from a soft search.

ClearScore is a credit broker, not a lender.

Improving your credit profile before applying

• Register on the electoral roll at your current address. This simple step can help improve your credit score.

• Pay all bills on time for at least three months before applying. Setting up direct debits can help you avoid missed payments.

• Reduce credit card balances where possible, especially if your utilisation is high. High credit utilisation may concern mortgage lenders.

• Avoid new credit applications in the months before your mortgage application. Multiple searches can suggest financial pressure to lenders.

• Check your credit report for errors and dispute any inaccuracies with the relevant credit reference agencies.

After you get your AIP: what next?

How to use your AIP when house hunting

Once you have your AIP, you can start viewing properties within your indicated budget. Many estate agents will ask to see your AIP before negotiating offers on your behalf, as it shows you're a credible buyer. Keep a digital copy on your phone for easy sharing.

Your AIP doesn't lock you into one lender. You're free to apply for a full mortgage with a different provider once you've found a property, although you may want to start with the lender who issued your AIP, as you've already cleared their initial checks.

Why is my mortgage in principle so low?

If your AIP comes back lower than you expected, it can feel disappointing, but it usually points to specific issues you may be able to address. Common reasons include:

• Income multiples: It’s widely believed that lenders offer 4 to 4.5 times annual income, which is generally true - however this is not the case for everyone, individual circumstances apply. Higher multiples generally need exceptional circumstances or specialist lenders.

• Monthly affordability: Lenders stress-test your budget assuming higher interest rates. High monthly commitments can reduce borrowing capacity.

• Credit score impact: Lower scores can restrict both borrowing amounts and the lenders available to you.

• Deposit size: Smaller deposits mean higher loan-to-value ratios, which some lenders limit.

• Employment type: Contractors, freelancers, and recent job changers may face stricter lending criteria.

What to do if your AIP is declined

An AIP decline isn't the end of the road. Common reasons include credit file issues, affordability concerns, or simply not meeting a particular lender's criteria. Steps you can take include:

• Ask the lender for feedback on why the application was declined (they're not always required to share this, but some will).

• Review your credit report for errors or recent changes that may have triggered the decision.

• Wait a few weeks before reapplying to avoid multiple credit searches stacking up on your file.

• Consider speaking to a mortgage broker, who may be able to identify lenders better suited to your circumstances.

• Work on the underlying issues, whether that's reducing debt, building up a larger deposit, or improving your credit profile.

Should you get more than one AIP?

There's no legal limit on AIPs, but applying for too many isn't usually advisable. Each hard credit search can temporarily lower your score, and multiple applications in a short window might concern lenders. A common approach is to apply to two or three lenders within a short period to compare options. If you need to approach additional lenders, consider spacing out applications by at least a few weeks.

From AIP to full mortgage application

Once you've found a property and had your offer accepted, you'll submit a full mortgage application. This involves detailed verification of everything you stated in your AIP. Lenders check bank statements, payslips, and other documents to confirm your financial position.

The property valuation also happens at this stage. If the surveyor values the property below your purchase price, you may need to renegotiate or find additional deposit funds. Full applications include detailed affordability assessments and stress testing at higher interest rates, to confirm you could manage payments if rates were to rise.

Documents you'll need for the full application

• Income proof: Three months of payslips, P60, and employment contract for employed applicants. Self-employed applicants typically need SA302 forms and business accounts.

• Bank statements: Three to six months showing salary payments, regular outgoings, and the source of your deposit.

• Identification: Passport or driving licence plus recent utility bills for address verification.

• Property information: Purchase contract, survey results, and legal representative details.

• Deposit proof: Bank statements showing savings accumulation, and gift letters if family members contributed.

Will my AIP definitely convert to a full mortgage?

Not always. While many AIPs do convert to full approvals when circumstances haven't changed, the full application involves deeper checks. Outcomes can vary based on the property valuation, document verification, and any changes to your financial situation between AIP and application.

Tools like ClearScore can help you keep an eye on your credit report throughout this process. Any changes between your AIP and full application could affect your approval or the rates offered.

Using ClearScore to support your application

Whether you're preparing to apply for an AIP, working on your credit profile, or considering other borrowing options alongside your mortgage, ClearScore offers free tools that can help.

You can check your credit score and report for free, for life. ClearScore also lets you explore loans and credit cards matched to your credit profile, which can help you compare options before applying.

Through its Triple Lock feature, ClearScore offers pre-approved offers on selected products, which can give you more confidence about your eligibility before you apply.

Important: Pre-approval doesn't always guarantee acceptance and is subject to lenders' checks of your credit status.

Frequently asked questions

Is a mortgage in principle a guarantee?

No. An AIP is a conditional indication of what a lender may be willing to offer, based on the information you provide. The final decision depends on full checks, including verification of income and a property valuation.

Does a mortgage in principle affect my credit score?

Most AIPs use a soft credit search, which doesn't affect your credit score. Some lenders run a hard search at AIP stage, which can leave a footprint on your file, so it can be worth checking which type of search is used before applying.

How long does a mortgage in principle last?

Most AIPs are valid for 60 to 90 days. After that, you'll usually need to renew or reapply, especially if your circumstances have changed.

Can I get a mortgage in principle with bad credit?

It's possible, but options may be more limited. Some specialist lenders work with applicants who have a less established or impaired credit history. Reviewing your credit report first and speaking to a mortgage broker can help you understand which lenders are most likely to consider your application.

What's the difference between an AIP and a mortgage offer?

An AIP is a conditional indication based on the information you provide and a light-touch credit check. A mortgage offer is a formal, binding commitment from a lender, issued after they've verified your documents, checked your finances in detail, and valued the property you want to buy.

Can I get an AIP without a property in mind?

Yes. In fact, many people get their AIP before they start viewing properties, so they have a clear idea of their budget and can move quickly when they find the right home.

Can I check my credit score before applying for a mortgage?

Yes. You can check your credit score for free with services like ClearScore, which uses Equifax data in the UK. This can help you understand your starting position and identify any issues to address before applying.

Important information

This article is for general information only and does not constitute financial advice. The right mortgage for you will depend on your individual circumstances. You may wish to speak to a qualified mortgage adviser before making any decisions. Your home may be repossessed if you do not keep up repayments on your mortgage.

Pre-approval doesn't always guarantee acceptance and is subject to lenders' checks of your credit status.