We’ve all fallen down the Zoopla or Rightmove rabbit hole. One minute you’re just having a nosy at your neighbour’s house, the next you’re deep into the “dream home” filter settings and wondering if you could make the £1M renovation project work.
When you’re actually ready to start the home buying journey, it’s easy for your budget to creep up while browsing. But when it comes down to it, the business end of buying a home comes down to one simple question: how are you paying for it?
Buying a house: cash vs mortgage explained
It is possible to buy your home outright with cash, no debt, no mortgage (and yes, pick your jaw up off the floor). It’s not just for the ultra-wealthy; some people do manage it through years of saving, selling another property, or receiving an inheritance.
But for most of us, buying a home means paying a cash deposit and taking out a mortgage to cover the rest.
What is a house deposit and how much do you need?
A cash deposit usually comes from saving, saving, and a bit more saving. It might also come from selling a previous home, getting a work bonus, receiving a gift, or inheritance.
The rule of thumb?
💰 The bigger your deposit, the smaller your mortgage and the less interest you’ll pay over time.
How a mortgage works when buying your first home
A mortgage is a loan that covers the rest of the property’s purchase price after your deposit.
Example: you find a home for £100,000, you’ve saved £10,000 (plus extra for legal fees and taxes), so you’ll need a mortgage for £90,000.
Your home acts as security for the loan, which means if you miss repayments, the lender could repossess and sell it to recover what’s owed.
Key things to know about mortgage products in the UK
Mortgage providers (usually banks or building societies regulated by the FCA) call their loans products. Each one comes with slightly different features, but these are the three big ones to know:
- Term – how long the mortgage lasts.
Longer term = smaller monthly payments but more interest over time.
Example: a 35-year mortgage can cost over £100,000 more in interest than a 15-year one. - Interest rate – the cost of borrowing the money.
- Fixed rate period – how long your interest rate stays the same before you can switch or face an early repayment charge.
Example: you take a 25-year mortgage with a 3-year fixed rate at 4%.
For those 3 years, your rate is locked in. If you sell or switch early, you might pay a fee. Once the 3 years are up, your rate moves to the lender’s standard variable rate (usually higher), unless you remortgage to a new deal.
How to find the best mortgage deals in 2026
Here’s a smart order to follow:
- Start online – browse mortgage comparison sites to see what’s available.
They’ll earn commission if you apply through them (that’s fine), but remember they might show deals they get paid more for. - Speak to a mortgage broker – show them what you’ve found. A good broker can access deals that aren’t available directly to the public and help you navigate the process.
Ask: are they qualified, do they charge a fee, and can they search the whole market? - Check your own bank – they might offer special deals for existing customers.
- Compare and choose – remember, you’re shopping for the biggest loan of your life. You’re not begging for approval; you’re picking a product that works for you.
How much mortgage can you afford? (The 30% rule)
Just because a lender offers you four times your salary doesn’t mean you should take it.
A good rule: your monthly mortgage payment shouldn’t be more than 30% of your take home pay. Anything higher will squeeze your budget and limit your ability to save, invest, or build wealth later.
Length of time in debt
If you’re following the Financielle way, the goal is to become completely debt-free.
A shorter mortgage term means you’ll pay more each month but clear the debt sooner. A 15-20 year term is a good balance, and if you can, make small overpayments to cut down the interest and shorten the timeline even further.
How to prepare your finances before applying for a mortgage
Mortgage applications involve a deep dive into your finances but lenders aren’t trying to trip you up, they just have rules to follow.
3-6 months before applying, make sure you’re showing:
- Stable income that meets affordability checks (most lenders offer up to 4x your household income).
- No, low or well-managed debt, with consistent, on-time payments.
- Financial control – no dipping into your overdraft, regular bill payments, and sensible spending patterns.
Does your credit score affect getting a mortgage?
Lenders will look at your credit history, but don’t panic. A low score because you’ve not had much credit history isn’t a dealbreaker. What matters more is no missed payments, CCJs, or defaults.
Ignore the myth that you need to take out debt just to build a credit score. We’ve got a full guide on how to build credit without borrowing money.
Buying a home is a huge milestone and while the process can feel overwhelming, understanding how deposits and mortgages actually work makes it so much easier to plan for.
Head into the Financielle app and create your Home Buying Goal in the free tracker to start building your deposit and getting mortgage-ready.