Skip to content

What is a mortgage?

Many people dream of having a home to call their own, but the first step on the road to property ownership is applying for a mortgage. We explain the basics to help you understand how mortgages work and the different types available.

Many people dream of having a home to call their own, but the first step on the road to property ownership is applying for a mortgage. We explain the basics to help you understand how mortgages work and the different types available.

Written by
Alex Hasty
Insurance comparison and finance expert
Last Updated
27 JULY 2023
10 min read
Share article

What is a mortgage?

A mortgage is a type of loan you use to buy a property. As most people can’t afford to buy a home outright, a mortgage is a way to get your own home without having to pay upfront.

To get a mortgage, you’ll be expected to put down a deposit, usually at least 10% of the property’s value. A bank or building society could lend you the rest of the money you need – as long as you meet their mortgage-lending criteria.

Did you know?

The word ‘mortgage’ dates back to the 14th century. It literally means ‘death pledge’ – a combination of Old French (mort, meaning ‘death’) and Middle English (gage, meaning ‘pledge’). Essentially, a mortgage is a pledge that the loan will die once it has been paid off in full.

How does a mortgage work?

When you get a mortgage, you’ll have to pay back the loan – plus interest – in monthly instalments. This is done over a set number of years – typically 25 – but could be longer or shorter. You won’t fully own the home until the whole mortgage debt is paid off.

The interest rate you’ll pay, also known as the mortgage rate, is determined by a range of factors, including:

  • The Bank of England base rate
  • The length of mortgage, known as the ‘mortgage term’
  • The deposit amount
  • The level of risk to the lender
  • Whether it’s a variable or fixed-rate deal.

While you can’t control the rate of interest you’re offered, you can affect how the lender sees you as a borrower by building your credit score. Your mortgage provider will check before deciding whether or not to lend you money.

If you have a reliable track record of paying back debt, you’ve proven yourself to be a responsible borrower and might be able to benefit from lower interest rates. A large deposit also makes you less risky to lenders, so the more deposit you can save, the better the interest rate you’re likely to get.

Read our guide on how to save for a mortgage deposit.

Your home may be repossessed if you do not keep up repayments on your mortgage.

Did you know?

If you’re under the age of 40, a Lifetime ISA (LISA) could be one way of saving for a deposit. For every year you save money into a LISA, the government will add a 25% bonus to your savings, up to a maximum of £1,000 per year.

Mortgage types explained

There are two main types of mortgage – fixed rate and variable rate.

Fixed-rate mortgages

This type of mortgage has an interest rate that stays the same throughout the length of your introductory deal – typically between two and five years. After this, you’ll automatically move on to the lender’s standard variable rate, which is likely to be higher, unless you switch to a new deal.

A fixed-rate mortgage could help you budget as you’ll know what your repayments will be each month. But as the rate is fixed, you won’t benefit if interest rates fall.

Variable-rate mortgages

These mortgages have interest rates that can change at any time. This means your monthly mortgage payments could go up or down.

Different types of variable-rate deals include:

  • Tracker mortgages – the interest rate is tied to the Bank of England base rate
  • Discount mortgages – the interest rate is set at a percentage below the lender’s standard variable rate.

With a variable-rate mortgage, you might benefit from low monthly repayments if interest rates are low, but your repayments may rise steeply if interest rates go up.

What is a mortgage LTV?

The LTV, or loan-to-value of a mortgage, is the ratio between the size of the mortgage you take out and the value of the property. LTV is always shown as a percentage.

If you want to buy a house worth £250,000 and you have a deposit of £50,000, you’ll need to borrow £200,000. Your deposit is 20%, so your LTV will be 80%. This means that you need to look for a mortgage deal with an 80% LTV.

Typically, the best interest rates are offered to those with a lower LTV.

What is a remortgage?

A remortgage is when you switch to another mortgage deal, using the same property as security. You can remortgage with the same lender or a different provider.

Most people remortgage when they come to the end of their fixed-rate deal. This could be to get a better interest rate, cheaper monthly repayments or to free up cash by releasing equity in their home.

What’s the difference between a repayment mortgage and an interest-only mortgage?

Both fixed-rate and variable-rate mortgages are available on a repayment or interest-only basis. These work in different ways.

Repayment mortgages

With a repayment mortgage, your monthly payment is made up of both the capital that was lent to you and the interest, which is paid back until you’ve cleared the balance at the end of the mortgage term. This is the most common type of residential mortgage.

Interest-only mortgages

With an interest-only mortgage, you only pay the interest charged on your mortgage each month. So, when the mortgage term ends, you’ll still have to pay back the amount you originally borrowed (the capital).

You’ll need to have a plan in place to do so in order to get an interest-only mortgage – for example, an investment like an ISA. Interest-only mortgages are not as common as repayment mortgages.

An interest-only mortgage may seem more affordable as it will have lower monthly costs than a repayment mortgage. But you’ll need to provide evidence to the lender of how you’ll pay off the capital balance at the end of the mortgage term.

‘Part and part’ mortgages, where the loan is split between a repayment and interest-only mortgage, are also available.

Will I be able to get a mortgage?

Lenders will want to know whether you can afford to pay a mortgage before they agree to lend to you. To assess this, they’ll look at a variety of factors, including how much you want to borrow and what deposit you have.

They’ll also look at:

  • Your income
  • Your employment status
  • Your expenditure
  • Your credit rating.

To be as sure as they can that you can pay your mortgage, they’ll ‘stress test’ your finances to see if you could continue to pay if interest rates went up.

The type of property you’re buying – for example, a flat, house or new-build – will also be considered as some lenders might have their own rules about types of property they’re more or less willing to lend on.

Find out more about what makes you eligible for a mortgage.

Get a rough idea of how much you could borrow with our mortgage calculator.

What is a mortgage agreement in principle?

An agreement in principle (AIP) is a written statement from a lender saying they’re willing to lend you a certain amount of money, subject to full affordability checks.

To get one, you’ll need to provide information about your finances, including your income and outgoings. This is usually a soft credit check, so it shouldn’t affect your credit score.

How do I use an agreement in principle?

AIPs are used in the mortgage application process and are one of the first things you need to obtain before you start researching mortgages in detail.

However, an AIP is not a formal mortgage offer and there’s no guarantee your application will be accepted. It only gives you an indication of how much you could borrow. Having an AIP in place could also be useful to show estate agents and sellers that you’re serious about buying a property.

Once you’ve found a property within your budget, you can go back to the lender – or another lender of your choice – to make a formal mortgage application.

See how to apply for a mortgage.

What is a mortgage offer and how does it work?

After you’ve found a property, you can apply in full for a mortgage. You’ll get a mortgage offer as a formal response from the lender, setting out the terms and conditions of the offer. How much they’ll lend on a particular property will depend on a valuation of that property.

Most mortgage offers last around three to six months, to give you time to go through the legal process and complete buying your new home. If you don’t manage to buy the property during that time, you might need to ask for an extension. Some lenders may want to recheck your situation to see that what they’re offering is still affordable.

If you’re opting for new-build, you might be able to get a longer mortgage offer. If this is the kind of home you want to buy, it’s worth asking when you apply for a mortgage.

What else do I need to think about?

Be aware that mortgages come with fees and charges that you’ll need to factor into your budget. These may include:

  • A valuation fee to cover the cost of valuing the property you want to buy
  • A booking fee, which is sometimes charged to secure a mortgage
  • An arrangement fee for setting up the mortgage.

Find out more about mortgage costs and fees.

How can I improve my chances of getting a mortgage? 

While each lender has its own criteria, all will want proof that you can be a reliable borrower and can afford your repayments.

Here’s a few ways to help improve your chances of getting a mortgage approval: 

  • Check your credit report before you apply – a mortgage lender will look at your credit history when reviewing your application to see how you manage your debts and repayments. If your credit score isn’t up to scratch, take a few months to improve it before applying for a mortgage.
  • Get on the electoral roll – lenders use the information on the electoral roll to confirm your identity. If you’re not registered to vote, it’s very unlikely you’ll be accepted for a mortgage.
  • Pay your bills on time – missed or late payments will harm your credit score and lessen your chances of being accepted for a mortgage.
  • Be careful about applying for credit – recent applications for credit cards or loans will show up on your credit file. If you make multiple applications and they’re rejected, it could indicate to a lender that you’re desperate for money and your mortgage application may be declined.
  • Repay any unsecured debts before you apply – paying off any outstanding balances on your credit cards and overdraft will not only help boost your credit score, but will also reduce your monthly outgoings, helping you to meet the affordability requirements of mortgage lenders.
  • Consider ‘Help to Buy’ – the government’s mortgage guarantee scheme could be an easier way of getting on the property ladder with just a 5% deposit.

Where can I get a mortgage?

Mortgages are offered by financial institutions, like banks and building societies. You can apply for a mortgage directly with the lender, compare deals through our comparison site or get advice from an independent mortgage broker.

A mortgage broker is a professional financial advisor who can find and apply for a mortgage deal on your behalf. Some are whole-of-market brokers, which means they look at the entire mortgage market and recommend the right deal for you. Be aware that some brokers can charge a fee for finding a mortgage, so check before you agree to use them.

Compare the Market has partnered with London & Country Mortgages Ltd (L&C)**, an award-winning broker, to provide you with fee-free mortgage advice.

Go to L&C mortgages

**London & Country Mortgages Ltd (L&C) is a multi-award winning mortgage broker with over 20 years’ experience in helping people secure their perfect mortgage. Advice is provided by L&C, who are authorised and regulated by the Financial Conduct Authority (143002).

L&C is not part of Compare the Market Limited. Compare the Market receive a % of the commission that our partner London & Country earns. All applications are subject to lending and eligibility criteria.

L&C will not charge you a broker fee should you decide to proceed with a mortgage.

All applications are subject to status and lending criteria and are based on your individual circumstances. Applicants must be 18+ and a UK resident.

Frequently asked questions

What’s the difference between a loan and a mortgage?

A loan refers to any financial transaction where you borrow a sum of money and agree to pay it back. A mortgage is a type of loan used to buy a property.

An ‘unsecured loan’, like a personal loan, allows you to borrow money  – usually up to £25,000 – without having to use a valuable asset like your home or car as collateral.

A ‘secured loan’, like a homeowner loan, allows you to borrow a larger sum of money, but you’ll need to use your home as security. This means your home could be repossessed if you can’t keep up with the repayments. So, essentially a mortgage falls under this category.

What is porting a mortgage?

Porting a mortgage is when you move home and take your existing mortgage with you. Not all lenders let you port your mortgage, so if you want the option, check before committing to a mortgage deal.

What is a guarantor mortgage?

A guarantor mortgage is where a family member or close friend guarantees to cover your mortgage repayments if you can’t.

A guarantor mortgage is an option if you’re a first-time buyer or you have a poor credit history. As your guarantor is offering security for the loan, there’s less risk for the lender and more chance of you being approved for a mortgage.

However, this type of mortgage is a huge financial commitment for your guarantor. They must be a homeowner themselves – and if your mortgage payments can’t be met be either of you, you both risk losing your homes.

What is an Islamic mortgage?

An Islamic or ‘halal’ mortgage is a type of home purchase plan (HPP) that is compliant with Sharia law. Unlike a traditional home loan, it doesn’t involve paying interest. This is because making money from money goes against Islamic ethical, social and religious beliefs.

An Islamic mortgage offers Muslims a Sharia-compliant way to buy a home in the UK. However, it’s also an option for non-Muslims looking for more ethical banking products.

How many mortgages can I have on my home?

In theory, you could have as many mortgages as you can afford on your home.

You could take out a separate homeowner loan in addition to your regular mortgage. This is known as a second charge or second mortgage.

Unlike a remortgage, when you switch your existing mortgage to a new deal, a second mortgage means you’ll have two (or more) loans on the same property.

You’ll only be able to take out a second mortgage if you have enough equity in your home. As it’s a brand-new loan, there are also new mortgage costs and fees to consider. Second-charge mortgages also tend to come with higher interest rates.

The content written in this article is for information purposes only and should not be taken as financial advice. If you require support on the products discussed here, please speak to your bank/lender or seek the advice of an independent professional financial advisor. We also have more information on our Customer Support Hub.

Looking for a mortgage?

Compare mortgages in minutes to see if you can save.

Compare now

Alex Hasty - Insurance comparison and finance expert

At Compare the Market, Alex has had roles as Commercial Associate Director, Director of Trading and Director of Growth. He’s currently responsible for the development and execution of Comparethemarket’s longer-term strategic options, ensuring the right breadth of products and services that meet customer needs.

Learn more about Alex

Compare mortgages quickly and easily Start comparing