What a mortgage in principle is, and what it is not
Estate agents will ask for one before they take your offer seriously. It is useful, and it is not the thing most buyers think it is.
A mortgage in principle is a lender's written indication of what they would probably lend, based on a credit check and the figures you supply. It is not a mortgage offer and it can be declined at full application. Most last 30 to 90 days. Some lenders use a soft credit check and others a hard check.
What it is
A mortgage in principle is a lender's written indication of what they would probably lend you. It is based on a credit check and the figures you give them.
It is also called an agreement in principle or a decision in principle. All three mean the same thing.
Estate agents ask for one because it separates serious buyers from browsers. Without one, an offer on a competitive property often gets ignored.
What it is not
- Not a mortgage offer, which comes after a full application and valuation
- Not a guarantee that the lender will lend that amount
- Not tied to a particular property, because no valuation has happened
- Not permanent, since most last 30 to 90 days
- Not proof your income has been verified, because most are based on what you type in
A mortgage in principle can be declined at full application. The usual reasons are income that does not match what was declared, or something on the credit file the soft check did not surface.
Where it sits against the real thing
| Stage | What it proves | How long it takes |
|---|---|---|
| Mortgage in principle | A lender would probably lend this much | Can be as quick as an hour |
| Full application | You have asked a lender to lend | Days |
| Valuation | The property is worth roughly the price | Varies |
| Formal mortgage offer | The lender has committed, subject to conditions | Varies by lender |
Only the last line is a commitment. Estate agents ask for the first one because it filters out people who have not started.
Want this checked against your own situation?
Send us a message and we can introduce you to a separately authorised firm that can look at your figures.
Ask us a questionPrefer WhatsApp? Message us there. We are open Monday to Saturday, 9am to 8pm.
This goes to a separately authorised firm we have vetted. The introduction costs you nothing. If you go ahead, we may be paid a fee by that firm.
Does it hurt your credit score?
Some lenders use a soft credit check for a mortgage in principle, which does not leave a mark on your file.
Others use a hard check, which is visible on your file. Several hard checks in a short window can look like a problem.
Ask which type the lender uses before you apply. Do not collect several from different lenders without checking.
How to get one that holds up
Check your credit file first
Correct any errors before a lender sees them. Our credit score page covers what to look for.
Have your real figures ready
Gross income, all credit commitments, childcare, and the deposit amount and source.
Be accurate rather than optimistic
An inflated figure gets you a certificate that falls apart at full application.
Ask about the credit check type
Some lenders use soft checks and some use hard checks, so ask which before you apply.
Note the expiry date
Most last 30 to 90 days.
Where you stand
- Offering on anything competitive
- Booking viewings you cannot afford
- Committing to a price range in your head
- An estate agent asks
- You inflated any figure to get a bigger number
- Your income is complex or recently changed
- The property type is unusual or non-standard
- It was issued more than three months ago
Check broadband before you make an offer in Principle?
Broadband speeds can vary street by street in Principle?, so check the exact address before you commit. Ofcom's free checker shows which broadband speeds and mobile coverage are available at any UK property.
Want all your bills in one?
We can introduce you to a specialist who can combine your mobile, broadband and utilities into one bill. There's no fee for the introduction.
We don't provide these services ourselves. Switching household bills is not a regulated financial service, so FCA protections and the Financial Ombudsman do not apply. We'll only pass your details to the specialist if you ask us to. See our privacy notice.
Questions people actually ask
What is a mortgage in principle?
Does a mortgage in principle affect my credit score?
How long does a mortgage in principle last?
Can I be refused after getting one?
Do I need one before viewing houses?
How do I check broadband speed at a property in Principle??
Where to go next
- MoneyHelper (Money and Pensions Service)
- GOV.UK, Credit scores and your credit file
- MoneyHelper, Budget planner
Figures checked on 1 September 2026 and correct for the 2026/27 tax year. Rates change, so check the source before you act on a number.
Want a figure you can rely on?
We will introduce you to a mortgage adviser who can get one in place and tell you which lenders fit your situation.
Start a conversationPrefer WhatsApp? Message us there. We are open Monday to Saturday, 9am to 8pm.
This goes to a separately authorised firm we have vetted. The introduction costs you nothing. If you go ahead, we may be paid a fee by that firm.