How Much Are Monthly Repayments and Income Requirements for a £300,000 Mortgage?

If you’re looking at a £300,000 mortgage, you’re probably asking two things straight away:
“What will my monthly repayments be?” and “What salary do I need to get approved?”

We get asked these questions at Mortgage Bridge all the time. We work with all sorts of clients — people with bad credit, complex income, or just looking for the cheapest £300,000 mortgage rates — and we know the numbers inside out.

So, let’s go through everything you need to know — repayments, income requirements, deposits, lender criteria, and a few tips to help you get that approval.


How Much Are Monthly Repayments on a £300,000 Mortgage?

Your monthly payment depends on:

  • The interest rate your lender offers
  • The term (how long you spread the mortgage over)
  • Whether it’s repayment or interest-only

Most people go for a repayment mortgage, which means you’re paying off the balance bit by bit. Interest-only has smaller monthly payments, but you’ll still owe the full £300,000 at the end.


What Would My £300,000 Mortgage Repayments Look Like?

Here’s an idea of what your repayments could be on a repayment mortgage:

Term3% interest4% interest5% interest6% interest
20 years£1,664£1,817£1,980£2,149
25 years£1,423£1,584£1,753£1,933
30 years£1,265£1,432£1,610£1,799
35 years£1,155£1,307£1,479£1,661

What this means:

  • Longer terms = lower monthly payments, but more interest in the long run.
  • Even a small change in rate can make a big difference.
  • If you can, making overpayments can cut years off your term.

What Salary Do I Need for a £300,000 Mortgage?

Lenders usually base borrowing on a multiple of your income — normally 4x to 4.5x, but sometimes up to 5x or 5.5x if you fit their criteria.


How Much Do I Need to Earn for a £300,000 Mortgage?

Lending MultipleRequired Annual Income
3.5x£85,715
4x£75,000
4.5x£66,667
5x£60,000
5.5x£54,545

A few things to remember:

  • These are based on having no other major debts. If you’ve got loans, credit cards, or childcare costs, the income needed might be higher.
  • If it’s a joint application, your incomes are added together.
  • Your credit history and spending habits also play a big part.

How Do Lenders Work Out Affordability for a £300,000 Mortgage?

Even if your salary fits the numbers above, lenders still do affordability checks. They’ll want to see:

  • Your regular monthly spending
  • Any debts you’re paying off
  • How stable your income is (especially if you’re self-employed or a contractor)
  • How many dependants you have

If your income is a bit more complex — maybe you’ve got multiple jobs or you’re self-employed — you’ll need extra documents like tax returns or accounts.


How Much Deposit Do I Need for a £300,000 Mortgage?

Your deposit affects both the interest rate you’ll get and which mortgage products you’ll be eligible for.


What Are Common Deposits for a £300,000 Mortgage?

  • 5% deposit (£15,000) – Higher loan-to-value (LTV), fewer lenders, higher rates.
  • 10% deposit (£30,000) – More choice and better rates.
  • 15% deposit (£45,000) – Even better rates and product availability.
  • 20% deposit (£60,000) – Usually where you’ll see the most competitive rates.

If you’ve got bad credit, a bigger deposit can really help your chances.


Should I Go Fixed or Variable for a £300,000 Mortgage?

You’ll have two main choices:

  • Fixed rate – Same payment every month for 2, 3, 5, or even 10 years. Great for budgeting.
  • Variable rate – Can change up or down with the market. Could be cheaper at times but can also go up suddenly.

For big loans like this, most people prefer the security of a fixed rate.


What Other Costs Should I Budget for with a £300,000 Mortgage?

Don’t forget the extras:

  • Lender arrangement or product fees
  • Valuation/survey fees
  • Solicitor/conveyancing costs
  • Stamp Duty (depending on the property price)
  • Buildings insurance (required by your lender)
  • Property upkeep and running costs

Can I Get a £300,000 Mortgage with Bad Credit or If I’m Self-Employed?

Yes — but it depends on your overall situation.

If you’re going for a £300,000 mortgage with bad credit, the lender will want to see proof you’ve been managing your finances well recently.

If you’re self-employed, you’ll likely need 1–3 years of accounts or tax returns. We work with specialist lenders who are much more flexible with this.


What Would a £300,000 Mortgage Look Like in Real Life?

Example 1 – 25 years at 5% interest:

  • £1,753 a month
  • £525,900 total over the term (£225,900 interest)

Example 2 – 30 years at 4% interest:

  • £1,432 a month
  • £515,520 total over the term (£215,520 interest)

How Can I Improve My Chances of Getting Approved for a £300,000 Mortgage?

Here’s what we tell our clients:

  1. Check your credit report for errors.
  2. Save as big a deposit as possible.
  3. Pay down other debts to boost affordability.
  4. Avoid applying for new credit before your mortgage.
  5. Use a whole-of-market broker (that’s us!) so you’re only going to lenders who are likely to say yes.

So, Can You Afford a £300,000 Mortgage?

  • Your repayments could be anywhere from around £1,155 to £2,149 a month depending on term and rate.
  • You’ll probably need a salary between £54,545 and £85,715 depending on the lender and your other commitments.
  • A bigger deposit means better deals and more lender choice.
  • Even with bad credit or complex income, we can often find a way forward.

If you’re ready to see what a £300,000 mortgage could look like for you, we can run the numbers, find the right lender, and guide you every step of the way.