You may hear an estate agent ask whether you have one before they will put an offer to the seller. So, what is a mortgage offer in principle? In most cases, people mean an Agreement in Principle, sometimes called a Decision in Principle (DIP) or mortgage in principle. It is an early indication from a lender of how much they may be prepared to lend you.
It can make you look more serious when buying a home, but it is not a final mortgage approval. The lender still needs to check the property, your documents and your full financial position before making a formal offer.
What is a mortgage offer in principle?
An Agreement in Principle is a provisional decision based on information you give a mortgage lender or broker. This usually includes your income, regular spending, employment details, deposit and outstanding borrowing. The lender uses this information, alongside a credit check, to estimate the maximum amount it could lend.
You might receive a certificate or reference number showing the amount agreed in principle. For example, a lender could say it is prepared in principle to lend up to £220,000, subject to full checks. That does not mean you can necessarily borrow that figure for every property you view.
The wording can be confusing because a formal mortgage offer is a separate, later stage. A formal offer is issued only after the lender has completed its underwriting and is satisfied with the property valuation and your evidence.
Agreement in Principle, mortgage offer and deposit
These three things work together, but they are not the same. Your deposit is the money you contribute towards the purchase price. The Agreement in Principle indicates possible borrowing. The formal mortgage offer confirms the lender is willing to lend on a particular property, subject to its stated conditions.
If you are looking at a £300,000 home with a £60,000 deposit, you may need a mortgage of £240,000. An Agreement in Principle for £240,000 can help you set a realistic search budget. It does not confirm the lender will value the property at £300,000 or accept every detail of your application.
What lenders look at before giving a decision
The process is often quick. Some lenders provide a decision online in minutes, while others take longer if they need more information. The speed should not be mistaken for a full assessment.
A lender will usually consider your earnings and whether they are stable, your employment status, existing credit commitments, household bills, deposit source and credit history. It will also look at the type and length of mortgage you want.
Most applications involve either a soft or hard credit search. A soft search is generally only visible to you on your credit report and should not affect your score. A hard search is visible to other lenders and may have a small, temporary effect, especially if several are made in a short period. Ask the lender or broker which type it uses before applying.
Self-employed buyers, property portfolio landlords and people with variable income may need to provide more detailed evidence later on. An Agreement in Principle can still be useful, but it is particularly wise not to assume an automated decision settles the question.
Why a mortgage in principle can help when you are buying
Having an Agreement in Principle shows that you have taken a sensible first step. Estate agents often ask for one before arranging viewings or accepting an offer, particularly where several buyers are interested.
It also gives you a clearer idea of what you may be able to afford. That can save time and disappointment by helping you focus on homes within reach, rather than falling in love with a property that would stretch your finances too far.
For sellers, an offer from a buyer with an Agreement in Principle may feel more reassuring than one from a buyer who has not spoken to a lender at all. But it is still only one part of assessing how secure a sale may be. The buyer may need to sell their own home, receive gifted-deposit evidence, pass further checks or resolve issues raised by the valuation.
Why it is not a guaranteed mortgage
A lender’s initial decision is based on limited information. Once you make a full application, it will ask for proof such as payslips, bank statements, identification, tax documents or accounts. Any difference between the original figures and the evidence can affect the outcome.
The property itself matters too. The lender will normally arrange a valuation to check that the home provides suitable security for the loan. If the valuation comes in below the agreed purchase price, the lender may reduce the mortgage amount. You may then need a larger deposit, need to renegotiate the price or choose another property.
Some properties can also create complications. Homes with short leases, significant structural concerns, certain construction types, Japanese knotweed, cladding issues or limited market appeal may be harder to mortgage. This is one reason a buyer can have an Agreement in Principle but still be unable to proceed with a particular purchase.
Changes in your circumstances between the initial decision and the full application can matter as well. Taking out car finance, missing a payment, changing jobs, reducing your hours or using more credit could alter the lender’s view. Until completion, it is usually sensible to avoid taking on new borrowing unless you have discussed it with your broker or lender.
How long does an Agreement in Principle last?
Most Agreements in Principle last between 30 and 90 days, although each mortgage lender sets its own period. If it expires before you find a property, you can often renew it. The lender may carry out another credit check and reassess your details.
Do not feel pressured to make an offer simply because your certificate is due to run out. A rushed purchase can bring far bigger consequences than renewing an Agreement in Principle. Instead, check when it expires and update it when you are still actively looking.
Mortgage rates and lending criteria can change during this time. An Agreement in Principle does not usually lock in an interest rate. A product is typically selected and reserved when you make the full mortgage application, though the exact process varies between lenders.
What to do before you apply
Start with an honest picture of your finances. Check your credit report for errors, add up your existing monthly commitments and make sure you understand where your deposit is coming from. If money is being gifted by family, the lender may need written confirmation and evidence of the source.
It helps to have key documents ready, particularly if your income is not straightforward. Employees may need recent payslips and P60s. Self-employed applicants commonly need tax calculations, tax year overviews and business accounts. Landlords may need rental income figures and details of existing buy-to-let borrowing.
A mortgage broker can be helpful where your circumstances are unusual, you have had credit difficulties or you are unsure which lenders may consider your application. They can explain the difference between headline borrowing figures and what feels manageable for your household each month.
If your sale depends on a buyer’s mortgage
If you are selling, particularly under time pressure, it is reasonable to ask whether a buyer has an Agreement in Principle and whether they are in a chain. However, be aware of its limits. It is not proof that the funds are guaranteed or that a completion date is secure.
This uncertainty can be difficult if you are dealing with probate, a vacant property, mortgage arrears, a difficult tenancy or a move with a fixed deadline. A conventional sale may still be the right route, but it can involve valuations, surveys, chains and the risk of a buyer withdrawing.
Where certainty and speed matter more than waiting for the highest possible offer, a direct property sale may be worth discussing alongside your other options. Quick Property Sale can talk through your circumstances without pressure, so you can decide what gives you the clearest way forward.
An Agreement in Principle is a useful starting point for buyers, not a finish line. Whether you are buying your next home or weighing up the reliability of an offer on yours, clear questions early on can prevent avoidable stress later.