How mortgages work: getting a mortgage A to Z

Getting a UK mortgage runs in clear steps: set your budget and deposit, get an agreement in principle, find a property, then make a full application with your documents. The lender values the property, underwrites your case and issues an offer, and a conveyancer handles the legal work to completion. The big levers are your deposit, your affordability, your credit history and the property. A regulated broker can guide each step.

This section is the plain-English A to Z: how the process works, whether to use a broker, how brokers are paid, what an agreement in principle is, how much you can borrow, and exactly what paperwork to have ready.

The journey, in order

  1. 1. Budget and deposit. Work out your deposit and a realistic price range.
  2. 2. Agreement in principle. A quick check that shows sellers you are serious.
  3. 3. Find a property and have your offer accepted.
  4. 4. Full application. Submit your documents; the lender underwrites and values.
  5. 5. Mortgage offer is issued, then conveyancing runs to exchange and completion.

Start here

Broker vs going direct The honest difference between a whole-of-market broker and applying to one lender. Do I need a broker? When a broker earns their keep, and when going direct is fine. How brokers get paid Fees, lender commission (procuration fees), and what to ask up front. Agreement in principle (AIP) What an AIP or DIP is, what it proves, and what it does not. How much can I borrow? A free affordability calculator, plus income multiples and the stress test explained. Mortgage repayment calculator Enter the loan, rate and term for the monthly payment, total paid and total interest. Overpayment calculator See the interest saved and the years cut off by overpaying your mortgage. Interest-only calculator The monthly interest cost, the balance still owed at the end, vs repayment. Loan-to-value (LTV) calculator Your LTV from price and deposit, and which rate band it falls in. Porting calculator Blend your ported deal with a top-up to see the real combined cost. Stamp duty calculator Slice-by-slice SDLT for standard, first-time and additional-property purchases. Porting a mortgage Take your existing deal to a new home, and when it beats a fresh remortgage. Mortgage underwriting What an underwriter checks after you apply, and how to give a clean case. Documents you need A checklist by borrower type: employed, self-employed, contractor.

Common questions

What are the steps to getting a mortgage?

In short: work out your budget and deposit, get an agreement in principle, find a property, then make a full application with your documents. A lender values the property, underwrites your case, and issues a mortgage offer. Your conveyancer handles the legal work through to completion. A broker can guide you through each step and pick the right lender.

Do I get the mortgage or does a broker?

You are the borrower. A broker advises you and submits the application on your behalf to a lender, but the mortgage is between you and the lender. MortgageExplained is not a broker or lender: we explain how it works, then introduce you to a regulated broker who can advise and arrange it.

How long does it take?

It varies, but from full application to mortgage offer is often a few weeks, and the whole purchase commonly takes a couple of months or more once conveyancing and searches are included. Being organised with your documents and responding quickly speeds it up.

What decides whether I am approved?

Mainly your deposit (which sets the loan-to-value), your income and outgoings (affordability), your credit history, and the property itself. Lenders differ a lot on each, which is why the same case can be accepted by one and declined by another.

New to buying? See first-time buyer mortgages. Coming up to a deal ending? See remortgage. Unsure of a term? Check the glossary.

AP

Adam Parker

Founder, MortgageExplained, MortgageExplained

Adam spent nearly a decade as a mortgage adviser at Just Mortgages, with further experience in commercial finance. He is CeMAP and CF qualified. He built MortgageExplained to do one thing well: explain mortgages in plain English, then introduce you to a regulated broker when you are ready. Every page is written and reviewed by Adam.

Last reviewed: 21 July 2026

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