Mortgage in Principle (Agreement in Principle) — How to Get One Fast

Pre-Approved Mortgage UK: What Is a Mortgage in Principle & How to Get One

In the UK, what American buyers call a “pre-approved mortgage” is known as a mortgage in principle — or sometimes an agreement in principle (AIP) or decision in principle (DIP). All three terms refer to the same thing: a conditional statement from a lender confirming how much they are prepared to lend you, before you have found a property or submitted a full mortgage application.

Getting a mortgage in principle before you start house hunting is not just useful — in a competitive market, estate agents often require one before they will arrange viewings, and sellers take offers from buyers with a mortgage in principle far more seriously than those without.

This guide explains exactly how to get a mortgage in principle, what the process involves, how long it lasts, and what happens next. If you want one arranged quickly, speak to one of our mortgage brokers — we can have a decision in principle issued the same day in most cases.

Contents

• Mortgage in principle vs agreement in principle — is there a difference?
• How to get a mortgage in principle — step by step
• Does a mortgage in principle affect your credit score?
• How long does a mortgage in principle last?
• Can I be declined for a mortgage after getting a mortgage in principle?
• What documents do you need for a mortgage in principle?
• What factors affect whether you get a mortgage in principle?
• FAQs

Mortgage in Principle vs Agreement in Principle — Is There a Difference?

No — mortgage in principle, agreement in principle (AIP), and decision in principle (DIP) all refer to the same document. Different lenders use different terminology, which is why buyers sometimes assume they are separate things.

• Mortgage in principle (MIP): The most commonly used term. Confirms a lender would lend you up to a stated amount.
• Agreement in principle (AIP): Used by many high-street lenders including Halifax and Nationwide.
• Decision in principle (DIP): Used by lenders including Santander and Barclays. The terminology suggests a slightly firmer assessment, but in practice all three mean the same thing.

None of these is a binding mortgage offer. The lender’s formal, legally binding offer only comes after you have had an offer accepted on a specific property and submitted a full mortgage application — at which point the lender carries out a full underwrite, including a valuation of the property.

“Pre-approved mortgage” is an American term that does not translate directly into the UK mortgage system. When UK buyers, estate agents, or lenders refer to pre-approval, they mean a mortgage in principle.

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How to Get a Mortgage in Principle — Step by Step

Getting a mortgage in principle is a straightforward process. Here is exactly how it works:

1. Check your credit report first.
   Before approaching any lender, check your credit file with all three UK reference agencies — Experian, Equifax, and TransUnion. Use a service like CheckMyFile to see all three reports in one place. Any errors on your file should be corrected before you apply — mistakes are surprisingly common and can affect the amount a lender will offer.
2. Decide whether to apply directly or through a broker.
   You can apply for a mortgage in principle directly with a lender, or through a whole-of-market mortgage broker. Going direct limits you to that lender’s own products. A broker searches the full market, knows which lenders are most likely to approve your application, and can often secure better rates than going direct. Critically, a broker can carry out a soft search with multiple lenders before committing to a hard search — protecting your credit file.
3. Provide your financial information.
   The lender or broker will ask for: your income (employed or self-employed), your regular outgoings, any existing debts (loans, credit cards, hire purchase), your deposit amount, and the approximate purchase price you are targeting. At this stage, you do not need to have found a specific property.
4. Credit checkA check of a borrower's credit history, which is used by mor... is carried out.
   The lender will carry out either a soft or hard credit check (see the section below on credit scores). A soft check does not affect your credit score; a hard check leaves a footprint. Most lenders now offer a soft search at the mortgage in principle stage.
5. Receive your mortgage in principle.
   If the initial assessment is positive, the lender issues a mortgage in principle document — usually within 24 hours, often same day. This confirms the maximum amount they would be prepared to lend, subject to full underwriting and property valuation. You can show this to estate agents when making offers.

The entire process from initial enquiry to receiving the document typically takes a few hours to one working day when done through a broker. Going direct to a high-street lender may take slightly longer due to processing queues.

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Does a Mortgage in Principle Affect Your Credit Score?

This is one of the most frequently asked questions about the mortgage in principle process — and the answer depends on whether the lender carries out a soft search or a hard search.

• Soft credit search: Does not leave a visible footprint on your credit file. Other lenders cannot see it. Your credit score is not affected. Many lenders now use soft searches at the mortgage in principle stage specifically to avoid penalising buyers who are shopping around.
• Hard credit search: Leaves a visible footprint that other lenders can see. Multiple hard searches within a short period can temporarily lower your credit score and may make other lenders more cautious. Hard searches are unavoidable at the full mortgage application stage.

When you apply for a mortgage in principle, always ask whether the lender will carry out a soft or hard search. Most reputable lenders and all brokers can clarify this before you proceed. If you are approaching multiple lenders directly, try to do so within a short window — credit agencies treat multiple searches close together as a single event for scoring purposes.

The hard credit search that matters most happens when you submit your full mortgage application after your offer has been accepted. At that stage, the hard search is unavoidable and expected — it will not significantly harm a good credit profile.

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How Long Does a Mortgage in Principle Last?

A mortgage in principle typically lasts between 60 and 90 days, depending on the lender. Some lenders issue them for as little as 30 days; others extend to 90 or even 180 days.

If your mortgage in principle expires before you have had an offer accepted, you will need to renew it. In most cases, renewal is straightforward — provided your financial circumstances have not changed significantly since the original application. Your broker can handle the renewal quickly.

Key things that can cause a mortgage in principle to lapse or be invalidated before expiry:

• A significant change in income (job loss, reduction in salary, going from employed to self-employed)
• Taking on new credit (car finance, a new credit card, a personal loan) that increases your monthly outgoings
• A deterioration in your credit score (missed payments, a new default or CCJ)
• A large change in the purchase price you are targeting (if significantly higher than the figure used in the original application)

The practical advice is: do not make any significant financial changes between getting your mortgage in principle and completing your purchase. Keep your financial profile as stable as possible throughout the process.

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Can I Be Declined for a Mortgage After Getting a Mortgage in Principle?

Yes — and this happens more often than buyers expect. A mortgage in principle is a conditional indication, not a guarantee. The lender reserves the right to withdraw or reduce the offer at the full application stage for several reasons:

• The full underwrite reveals issues not visible at the initial stage. The mortgage in principle is based on the information you self-declared. When you submit a full application, the lender scrutinises payslips, bank statementsA record of a borrower's financial transactions often requir..., tax returns, and your full credit file in detail. Discrepancies between what was declared and what the documents show can lead to a revised offer or a decline.
• The property fails the valuation. A mortgage in principle is not tied to a specific property. Once you have a property, the lender commissions a valuation. If the surveyor values the property below the agreed purchase price, the lender will only lend against the lower valuation figure — meaning you either need to renegotiate the purchase price or find additional funds.
• Your circumstances changed between application stages. Taking on new debts, losing your job, or a drop in your credit score after the mortgage in principle was issued can all result in the lender reassessing what they will offer.
• The property type is unacceptable to the lender. Some properties — non-standard construction, short leasehold, above commercial premises — are not accepted by all lenders. Your mortgage in principle does not account for property-specific criteria.

If you have had a mortgage in principle declined at the full application stage, do not reapply immediately with multiple lenders. Each application leaves a hard footprint. Speak to a specialist broker first — they will identify the reason for the decline and approach only the lenders most likely to approve your full application.

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What Documents Do You Need for a Mortgage in Principle?

At the mortgage in principle stage, lenders do not usually require physical documents — the assessment is based on the information you declare. You will need to have the following details to hand:

• Proof of income: If employed, your current salary and any additional income (bonusIncome received as a bonus, which may affect a borrower's ab..., commission, overtime). If self-employed, your approximate net profit over the last two to three years and your latest year’s tax calculation (SA302).
• Monthly outgoings: Regular committed expenditure — existing loan repayments, credit card minimum payments, hire purchase agreements, childcare costs, maintenance payments.
• Deposit amount: How much you have saved, and the source of the funds (savings, gifted deposit, Help to Buy, equityThe difference between the value of the property and the amo... from a sale).
• Target purchase price: An approximate figure for the type of property you are looking to buy.
• Credit history: You do not need to provide documents, but you should be aware of what is on your credit file. The lender will check this directly.

When you move to a full mortgage application after your offer is accepted, the lender will require physical documents to verify what was declared at the mortgage in principle stage — payslips, bank statements, proof of depositEvidence that a borrower has the required deposit to purchas..., and photo ID. Having these ready in advance speeds up the process significantly.

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What Factors Affect Whether You Get a Mortgage in Principle?

Lenders assess several elements to decide whether to issue a mortgage in principle and for how much. The key factors are:

• Income and income multipleA calculation used by mortgage lenders to assess how much a ...: Most UK lenders will lend up to 4–4.5 times your annual income. Some specialist lenders extend to 5.5–6 times salary for certain buyer profiles. For a joint application, combined income is used.
• Debt-to-income ratio: The proportion of your monthly income committed to debt repayments. Lenders prefer this to be below 40%. High existing debt reduces the amount a lender will offer even if your income is strong.
• Credit history: Late payments, defaultsMissed payments on credit accounts, which can affect a borro..., CCJs, or bankruptcy in your recent history will affect both whether you are approved and the rate you are offered. Adverse credit does not automatically prevent a mortgage in principle — specialist lenders assess adverse credit cases regularly.
• Employment status: Employed applicants are assessed most straightforwardly. Self-employed, contractor, and zero-hours contract applicants require more documentation and some lenders are less accommodating. A specialist broker knows which lenders are flexible on employment type.
• Deposit size: A larger deposit reduces the loan-to-value (LTV) ratio, which improves the lender’s risk position and typically results in a better rate. Most lenders require a minimum 5% deposit, though 10–15% opens up significantly more product options.

Advantages of Having a Mortgage in Principle

• Credibility with sellers: Sellers and estate agents take offers from buyers with a mortgage in principle far more seriously than those without one — particularly in competitive markets.
• Budget clarity: You know exactly the maximum you can borrow, allowing you to search for properties realistically and avoid wasting time on properties outside your budget.
• Faster progression: Having the mortgage in principle in place means you can move quickly once an offer is accepted, reducing the time between acceptance and mortgage application.
• Rate access: Some lenders allow you to reserve a specific mortgage rate at the mortgage in principle stage — protecting against rate rises while you search for a property.

FAQs — Mortgage in Principle & Pre-Approval UK

What is a mortgage in principle in the UK?

A mortgage in principle (also called an agreement in principle or decision in principle) is a written statement from a lender confirming how much they would be prepared to lend you, based on an initial review of your income, outgoings, deposit, and credit history. It is not a binding offer — the lender’s formal commitment only comes after a full application and property valuation. Most mortgage in principles are issued within 24 hours and last 60–90 days.

What is the difference between a mortgage in principle and an agreement in principle?

There is no difference — they are the same document. Different lenders use different names: mortgage in principle (MIP), agreement in principle (AIP), and decision in principle (DIP) all describe the same conditional lending statement. The terminology varies by lender, not by the nature or strength of the commitment.

Does a mortgage in principle affect your credit score?

It depends on the type of credit search the lender uses. A soft search — used by most lenders at the mortgage in principle stage — does not affect your credit score and is invisible to other lenders. A hard search leaves a visible footprint on your credit file. Always confirm which type of search will be carried out before proceeding. Multiple hard searches in a short period can temporarily reduce your score, which is why applying through a broker who can soft-search multiple lenders simultaneously is advisable.

How long does a mortgage in principle last in the UK?

Most mortgage in principle decisions last between 60 and 90 days. Some lenders issue them for 30 days; others for up to 180 days. If yours expires before you have an offer accepted, you will need to renew it — usually a quick process if your circumstances have not changed. Avoid taking on new debts or changing employment status during this period, as either could affect a renewal or the full application that follows.

Can I be declined for a mortgage after getting a mortgage in principle?

Yes. A mortgage in principle is a conditional indication, not a guarantee. Lenders can withdraw or reduce the offer at the full application stage if the full underwrite reveals discrepancies with what was declared, if the property fails the valuation, if your circumstances have changed since the MIP was issued, or if the property type falls outside the lender’s criteria. If this happens, speak to a specialist broker before reapplying — each new application leaves a hard search footprint on your credit file.

How do I get a mortgage in principle?

You can apply directly with a lender or through a whole-of-market mortgage broker. Check your credit report first, then provide your income, outgoings, deposit amount, and target purchase price. The lender runs a soft or hard credit check and issues the mortgage in principle, typically within 24 hours. Going through a broker gives you access to the full market, a soft search across multiple lenders, and expert guidance on which lenders are most likely to approve your full application later.

Can I get a mortgage in principle with bad credit?

Yes. Specialist lenders assess applications from borrowers with adverse credit histories — including CCJs, defaults, missed payments, and previous bankruptcy. You are likely to need a larger deposit (typically 15–25%) and will face higher interest rates. A specialist mortgage broker is essential in this situation — they know exactly which lenders consider adverse credit cases and will approach only those, protecting your credit file from unnecessary hard searches at lenders who would decline.

Do I need a mortgage in principle before making an offer on a house?

You do not legally need one, but in practice most estate agents and sellers expect buyers to have a mortgage in principle before their offer is taken seriously. In competitive markets, an offer accompanied by a mortgage in principle is demonstrably stronger than one without. It takes as little as a few hours to obtain through a broker — there is no reason to make offers without one.

What documents do I need for a mortgage in principle?

At the mortgage in principle stage, you typically do not need to submit physical documents — the lender assesses your declared information and carries out a credit check. You will need to know your income, monthly outgoings, deposit amount, and approximate target purchase price. Physical documents (payslips, bank statements, SA302s for self-employed applicants, proof of deposit) are required at the full mortgage application stage that follows an accepted offer.

What is the difference between a mortgage in principle and a full mortgage offer?

A mortgage in principle is a conditional indication based on declared information and a basic credit check — it is not tied to a specific property and carries no legal obligation. A full mortgage offer is a legally binding commitment from the lender to lend a specific amount, secured against a specific property that has passed valuation, after a full underwrite of all supporting documents. The full mortgage offer is what your solicitor uses to progress to exchange of contractsThe point at which the buyer and seller exchange signed cont....

Can I get a mortgage in principle before I have found a property?

Yes — this is exactly when you should get one. Obtaining a mortgage in principle before house hunting confirms your maximum budget, makes you a credible buyer in the eyes of estate agents, and means you can move quickly once you find a property you want. There is no need to have a specific property in mind when you apply. The mortgage in principle is not tied to any property until you submit a full application after an offer is accepted.