This guide provides general information and is not a substitute for personalised mortgage, tax or legal advice.
Written and reviewed by the Highhouse Money mortgage team · Last reviewed: 25 August 2026
An agreement in principle — sometimes called a decision in principle or mortgage in principle — is often the first formal document buyers get in the mortgage process. It gives an early indication of how much a lender might be willing to advance, based on limited information about your income, outgoings and credit history.
While it is not a mortgage offer and carries no guarantee, an agreement in principle is a useful and often expected step: it gives you a realistic budget, signals to estate agents that you are a credible buyer, and can highlight issues — such as credit history problems — early enough to address them before you commit to a property.
Before you apply for an agreement in principle
- Know your rough income, outgoings and deposit amount
- Check your credit reports for anything that might need explaining
- Ask whether the lender uses a soft or hard credit search
- Note the AIP's validity period so you know when it expires
- Avoid applying for new credit shortly before or after getting an AIP
- Keep the AIP document or reference number for your estate agent
- Treat the figure as indicative, not a promise, when setting your budget
What an agreement in principle actually is
An agreement in principle is a statement, usually issued quickly, indicating how much a particular lender might be prepared to lend based on the details you provide — typically income, outgoings, deposit and some information about your credit history. It is based on limited, sometimes self-declared information rather than a full underwriting review.
Because it is indicative rather than binding, an AIP should be treated as a useful planning tool and a signal to sellers and agents, not as confirmation that a mortgage will definitely be approved on those terms.
Agreement in principle versus full mortgage offer
| Agreement in principle | Full mortgage offer | |
|---|---|---|
| Based on | Limited, often self-reported information | Verified documents, income and credit checks |
| Credit search | Often a soft search (check with the lender) | Always a hard search |
| Property involved | No — general amount only | Yes — specific property, valued by the lender |
| Binding? | No — an indication only | Yes — a formal, conditional offer to lend |
| Typical timescale | Minutes to a day | Days to a few weeks, depending on complexity |
Process details vary between lenders — always confirm the specifics with the lender or your advisor.
Why estate agents ask for one
In a competitive market, estate agents and sellers often want reassurance that a buyer can realistically obtain the necessary finance before accepting an offer on a property. An agreement in principle is commonly used as that evidence, since it shows a lender has indicated a willingness to lend, at least in principle, based on your circumstances.
This is a practical, market-driven expectation rather than a legal requirement, but in many areas it has become close to standard practice before an offer will be seriously considered.
Soft searches, hard searches and your credit file
Many lenders use a soft credit search to produce an agreement in principle. A soft search leaves a record visible only to you, not to other lenders, and does not affect your credit score. This makes it possible to get an AIP, or even more than one, without it showing up as a series of credit applications.
Not every lender's AIP process uses a soft search — some use a hard search, which is visible to other lenders and can affect your credit score. Always check which type of search will be used before proceeding, particularly if you intend to compare more than one lender.
How long an agreement in principle lasts
Validity periods vary by lender, but AIPs are typically time-limited — often somewhere in the region of 30 to 90 days. If you haven't found a property or submitted a full application within that window, you may need to request a new one, which could produce a different figure if your circumstances or the lender's criteria have changed in the meantime.
What happens after you find a property
Once you have an accepted offer on a property, you move from the agreement in principle to a full mortgage application. This involves submitting proof of income, bank statements and identification, a hard credit search, and a valuation of the specific property. Only once all of this is verified will the lender issue a formal mortgage offer.
Your home may be repossessed if you do not keep up repayments on your mortgage. It is worth using the period after your AIP, but before a full application, to make sure the borrowing you are planning is genuinely comfortable, not just the maximum figure indicated.
What lenders may assess
- Declared income and outgoings at the AIP stage
- A soft or hard credit check, depending on the lender's process
- Deposit amount and intended property type
- At full application: verified documents, credit history and a property valuation
Every lender sets its own criteria, which change regularly. The points above are common themes, not a guarantee of how any individual lender will treat an application.
Frequently asked questions
What is a mortgage agreement in principle?
An agreement in principle (also called a decision in principle or mortgage in principle) is a statement from a lender indicating, based on limited information about your income and outgoings, how much it might be willing to lend you. It is not a formal mortgage offer and does not guarantee that a full application will be approved.
How is an agreement in principle different from a mortgage offer?
An agreement in principle is an early indication based on limited, often self-reported information, usually with a soft credit search. A full mortgage offer follows a complete application, with your income, outgoings and credit history verified, a valuation carried out, and a hard credit search performed. The AIP figure can change once the full underwriting process happens.
Do I need an agreement in principle before viewing properties?
It is not legally required, but many estate agents expect to see one before accepting an offer, as it demonstrates you are a serious, mortgage-ready buyer. Getting one early also gives you a realistic budget before you start viewing.
Does getting an agreement in principle affect my credit score?
Many lenders use a soft credit search for an agreement in principle, which does not affect your credit score and is not visible to other lenders. However, this is not universal — some lenders or products may use a hard search, so it is worth checking before you apply, especially if you plan to get more than one AIP.
How long does an agreement in principle last?
This varies by lender, but AIPs are typically valid for a limited period, often somewhere around 30 to 90 days, after which you may need to reapply if you haven't found a property or completed a full application. Check the validity period stated by the specific lender.
Can my agreement in principle amount change?
Yes. An AIP is based on information you provide, often without full verification. Once you submit a full application, the lender checks your documents, credit history and the property valuation, and the amount offered can be lower — or in some cases higher — than the AIP figure.
Can I get more than one agreement in principle?
You can typically apply to more than one lender for an AIP, which can be useful for comparing indicative amounts, especially if using a soft search that does not affect your credit file. Bear in mind that criteria and figures will differ between lenders, so comparing more than one can give a more rounded picture.
Does having an agreement in principle mean I'm guaranteed a mortgage?
No. An AIP is an indication, not a guarantee. A full application can still be declined or offered on different terms if your circumstances, the property, or the information verified during underwriting differ from what was initially assessed.
Sources and further reading
Where figures or rules can change, the position described is correct at the time of writing (25 August 2026) — always check the linked authoritative source for the latest position.
Related pages
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What comes next after your agreement in principle.
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Get a whole-of-market agreement in principle sorted quickly.
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Speak to an advisor before you start viewing properties.
Read moreTalk it through with an advisor
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