A mortgage in principle gives you an indication of how much a lender may be prepared to lend, based on the financial information you provide and, usually, a credit check. It can help you set a realistic property budget and show an estate agent or seller that you have already taken an important step towards arranging finance.
You may also see it called an agreement in principle, decision in principle or mortgage promise. Some people searching for mortgage pre-approval UK information mean much the same thing, although “pre-approval” is more common terminology in other countries. Whatever the label, it is not a guaranteed mortgage offer.
What does a mortgage in principle actually tell you?
A lender uses basic details about your income, regular spending, debts, deposit and circumstances to estimate how much it might lend. The result is normally a figure or range you can use as a starting point when looking at homes.
For example, suppose you have saved a £30,000 deposit and receive an agreement in principle indicating that a lender may offer up to £220,000. That does not automatically mean you should shop for a £250,000 property. You still need to allow for purchase costs and make sure the monthly repayments suit your household budget. The document gives you a firmer ceiling than simply guessing from a calculator.
A mortgage in principle is usually valid for a limited period. MoneyHelper says they commonly last around 30 to 90 days, although each lender sets its own rules. If yours expires before you find a property, you may be able to renew it or apply again.
Do you need one before viewing a property?
No. There is no general legal requirement to have a mortgage in principle before you view a home or make an offer. However, some estate agents may ask to see one, particularly in a competitive market, because it provides evidence that you have considered your borrowing position.
That makes a decision in principle useful even when an agent does not insist on it. A buyer who can show that a lender has already carried out an initial assessment may appear better prepared. It can also reduce the chance of viewing homes far outside your likely borrowing range.
It is sensible to arrange one shortly before you become serious about viewings rather than months in advance. That way, the information is more likely to reflect your current income, debts and deposit, and the document is less likely to expire before you need it.
How do you get a mortgage in principle?
You can usually apply directly to a bank or building society, or through a mortgage broker. Many lenders provide an online application that can be completed quickly if you have your information ready.
You will typically be asked for your name, date of birth, recent address history, employment details, income, regular outgoings, existing credit commitments and the amount of deposit you expect to use. The lender may also ask whether you are buying alone or jointly and whether you already own a property.
Accuracy matters. Do not round your salary up, leave out loan payments or underestimate committed spending just to obtain a higher figure. A full mortgage application involves more detailed checks, so inconsistencies can cause problems later.
Will it affect your credit score?
It depends on the lender. Many lenders use a soft credit search for an agreement in principle. A soft search is not normally visible to other lenders and does not affect your credit score in the way a hard application search can. However, MoneyHelper notes that some lenders may use a hard search, so check the lender’s process before applying.
This is especially useful if you are comparing options. Rather than submitting several applications without checking, ask whether each lender uses a soft or hard search at the mortgage-in-principle stage. That can help you avoid unnecessary hard searches in a short period.
Why an agreement in principle is not a mortgage offer
The most important limitation is that a mortgage in principle is provisional. It is based on a relatively early assessment and is not tied to final approval of a particular property.
After your offer on a home is accepted, you normally make a full mortgage application. The lender can then verify your income and other information in more detail, assess your credit history under its full underwriting process, and consider the property itself, including its valuation. Only after those checks can the lender issue a formal mortgage offer.
Your final borrowing amount can therefore be lower than the figure shown in your mortgage in principle, or the application can be declined altogether. Changes in employment, new borrowing, missed payments, a lower property valuation or a change in the lender’s criteria can all affect the outcome.
How to use your mortgage in principle sensibly
Treat it as a planning tool, not a spending target. The maximum a lender may be willing to lend is not the same as the amount you will feel comfortable repaying every month.
Before choosing your price range, compare the likely mortgage payment with council tax, utilities, insurance, maintenance and other household costs. Keep some savings aside for moving expenses and unexpected repairs instead of using every available pound for the deposit.
Before making offers, review how much deposit you need for a house, the main first-time buyer costs, and mortgage affordability based on your normal monthly spending.
FAQ
Is a mortgage in principle guaranteed?
No. It is an indication of what a lender may be prepared to lend based on initial information. A full application requires further checks, and the lender can change or decline its decision.
How long does a mortgage in principle last?
Many are valid for around 30 to 90 days, but the exact period depends on the lender. Check the expiry date on your document and reapply or renew it if necessary.
Can you make an offer without a mortgage in principle?
Yes. It is not a legal requirement, but an estate agent or seller may prefer evidence that you have explored your borrowing position. In a competitive sale, having one ready can strengthen your position.
Does a decision in principle mean the lender has approved the property?
No. The property is normally assessed later as part of the full mortgage application. A lender may refuse to lend the amount requested if its valuation or underwriting checks raise concerns.
Final thoughts
A mortgage in principle is best viewed as a bridge between early budgeting and a full mortgage application. It helps you narrow your search, gives estate agents and sellers more confidence that you are prepared, and can highlight borrowing limits before you become emotionally attached to a property.
Get one when you are close to actively viewing homes, provide accurate information, check whether the lender uses a soft or hard credit search, and remember that the figure is provisional. Used that way, it is a practical tool for making your home search more focused without mistaking an early indication for a final mortgage approval.