Decision in Principle Meaning: What a DIP Is and How It Works

A decision in principle is a lender’s early indication of how much it might be willing to lend you, based on a quick assessment of your circumstances. It’s not a loan offer and it’s not a guarantee. It tells you the size of finance a lender will likely consider before you commit to a full application.

You’ll also see it called an agreement in principle, a mortgage in principle, a DIP, or an AIP. The terms mean the same thing. The lender runs a light review of your income, deposit or equity, and credit profile, then gives you an indicative figure to work with.

That’s the short answer. The detail below explains what a decision in principle does, what it does not do, how long it lasts, and where it fits in a property finance deal.

What a decision in principle actually means

A decision in principle is the lender saying, on the information given so far, this is roughly what we would consider lending. It sits at the front of the borrowing journey, before valuation and before underwriting.

The lender looks at a few key inputs: your income or, for investment property, the rental coverage; the deposit or equity you’re putting in; and your credit history. From those, it produces an indicative loan amount and confirms whether you pass its early criteria.

A DIP carries weight because it shows you’re a serious buyer who has checked the numbers. Estate agents and auctioneers often ask to see one before they take an offer seriously. It does not, however, mean the money is approved.

What a decision in principle is not

This is where buyers get caught out. A decision in principle is not a binding loan offer.

The lender hasn’t yet valued the property. It hasn’t run full underwriting on your documents. It hasn’t verified your income evidence, your source of deposit, or your exit strategy. Any of those checks can change the outcome, reduce the figure, or lead to a decline at the formal stage.

So a DIP is a strong signal, not a promise. Treat it as confirmation that you’re in the right range with the right lender, then expect the full application to confirm or adjust the detail.

Does a decision in principle affect your credit score?

It depends on the type of credit check the lender runs.

Most lenders use a soft search for a decision in principle. A soft search is visible only to you, not to other lenders, and it doesn’t affect your credit score. You can get several soft-search DIPs without harm.

A minority of lenders run a hard search at the DIP stage. A hard search leaves a footprint on your credit file that other lenders can see, and several in a short window can dent your score. Always check which type of search a lender uses before you apply. A broker confirms this for you so a search is never wasted on a poor-fit lender.

How long does a decision in principle last?

A decision in principle typically lasts between 30 and 90 days, depending on the lender. Many run for 60 or 90 days, after which it lapses.

If your DIP expires before you find a property or before you complete, you renew it. That usually means a fresh check with updated information. Renewing is straightforward, but it matters on a slow purchase or a long search, because an expired DIP can stall an offer at exactly the wrong moment.

The clock is one reason timing matters. Get the DIP too early in a long search and it lapses. Leave it too late on a fast deal, such as an auction purchase, and you risk missing the window.

Decision in principle vs a full mortgage offer

These are two separate stages, and the gap between them is where most deals are won or lost.

A decision in principle is an early, light-touch indication based on a soft assessment. A full mortgage offer comes after the lender has valued the property, underwritten your case, and verified your documents. The offer is the formal commitment to lend on specific terms.

Between the two sits the work that actually decides the deal. The valuation can come back lower than expected and shrink the loan. The underwriter can question your income, your deposit source, or the property itself. On investment and development finance, the exit strategy gets stress-tested. A clean DIP doesn’t survive a weak full application.

This is why a DIP is a starting point, not a finish line. It opens the door. The packaged application gets you through it.

Where a decision in principle fits in property finance

A DIP is most associated with mainstream mortgages, including buy-to-let. Investors and landlords use one to confirm borrowing capacity before they bid or make an offer on a rental property.

The principle applies more loosely across other property finance, though the language differs. In bridging and development finance, the equivalent early stage is indicative terms or heads of terms. These set out the loan size, rate and structure a lender will consider before the full application. They play the same role as a DIP: an early read on whether the deal stacks up.

Across all these products, getting the early indication from the right lender first time is what keeps a deal on track. Vortex Finance arranges property finance through a panel of 100+ lenders, so the indicative figure you get is from a lender that actually fits your case, not the first one to say yes. For buy-to-let specifically, our guide to buy-to-let mortgages explains how lenders size the loan against rental coverage and stress-test it before they commit.

How to get a decision in principle that holds up

A DIP is only useful if the full application that follows it confirms the figure. Three things keep the two aligned.

Be accurate at the DIP stage. The early figure is built on the numbers you give. Inflate your income or understate your commitments and the underwriter corrects it later, usually downwards.

Match the lender to the case before you apply. A landlord with eight rentals, a first-time developer, and a business buying its premises all need different lenders. A DIP from the wrong lender is worthless when the full application fails its criteria.

Have your evidence ready. The documents that verify a DIP at full application are predictable: proof of income or rental coverage, proof of deposit or equity, ID, and an exit plan for short-term finance. Gathering them early means the full application moves fast once a property is agreed.

Frequently asked questions

What is a decision in principle in simple terms?

A decision in principle is a lender’s early indication of how much it might lend you, based on a quick check of your income, deposit and credit. It’s not a loan offer and not a guarantee. It shows you the rough borrowing figure to work with before you make an offer on a property.

Is a decision in principle the same as an agreement in principle?

Yes. Decision in principle, agreement in principle, mortgage in principle, DIP and AIP all describe the same thing: a lender’s early, indicative view of how much it may be prepared to lend before a full application.

Does a decision in principle guarantee I’ll get the loan?

No. A DIP is based on a light assessment before valuation and full underwriting. The lender can still reduce the figure or decline once it values the property and verifies your documents. Treat a DIP as a strong signal, not a commitment to lend.

How long does a decision in principle last?

Most decisions in principle last between 30 and 90 days, with 60 or 90 days common. When a DIP expires, you renew it with updated information. On a long property search or a slow purchase, expect to renew at least once.

Does getting a decision in principle hurt my credit score?

Usually not. Most lenders run a soft search for a DIP, which is invisible to other lenders and doesn’t affect your score. Some run a hard search, which leaves a footprint. Always check which a lender uses before you apply.

How long does it take to get a decision in principle?

Often minutes to a few hours for a straightforward case, once you provide your basic details. Complex cases, such as foreign income, a limited company structure, or prior credit issues, can take longer because the lender reviews more before giving an indicative figure.

Do I need a decision in principle to make an offer?

You don’t legally need one, but many estate agents and auctioneers ask to see a DIP before they take an offer seriously. It shows you’ve checked your borrowing capacity and can fund the purchase, which strengthens your position.

Vortex Finance is a whole-of-market property finance broker, not a lender. This guide is information, not advice. All figures and timescales are indicative and vary by lender. A qualified adviser will confirm the regulatory position of your specific case on a call.