Part and Part Mortgages: 4 Documents UK Professionals Should Prepare

IMPORTANT: YOUR HOME MAY BE REPOSSESSED IF YOU DO NOT KEEP UP REPAYMENTS ON YOUR MORTGAGE.

Yes, you can have a part and part mortgage in the UK, but the lender must be satisfied that any interest-only portion has a credible, documented repayment strategy. You still need to pass the normal affordability and credit checks, and the offer illustration must set out the interest-only arrangements. No lender is obliged to accept your application.

TL;DR:

Lenders require affordability and credit checks plus a documented repayment strategy; speculative house price growth does not qualify, and accepted repayment vehicles vary by lender.

The repayment portion reduces capital, while the other portion leaves its capital unpaid; offset savings lower interest but do not repay that balance.

If your plan falls short, lenders need not refinance; options include switching to repayment, extending the term, using savings, or selling.

Lower payments do not guarantee lower costs: the interest only balance accrues interest throughout the term, and financed fees accrue interest too.

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What is a part mortgage and why do people choose one?
Who can qualify, and what do lenders check?
How do UK rules and FCA guidance affect part interest-only mortgages?
Can you combine interest-only, repayment, offset and remortgaging?
What happens if your repayment strategy fails?
How do you check whether a part and part mortgage is right for you?
What are the typical scenarios and benefits for professionals?
How does a part and part mortgage differ from other mortgage structures?
How does complex income affect a part and part mortgage application?
What do successful part and part arrangements look like?
How does protection advice fit with part and part mortgage planning?
What fees and costs should you expect?
How can Haven Mark Advisers help with a part and part mortgage?
FAQ
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What is a part mortgage and why do people choose one?

A part and part mortgage splits one loan into two slices. The repayment slice reduces your capital every month. The interest-only slice covers the interest alone, so its capital balance stays the same until the end of the term, when you must repay it in full. Some people call this a part interest only mortgage.

People usually choose this structure for practical reasons:

To lower the monthly outlay for a period while still paying down part of the debt.
To bridge towards a sale, a bonus, an inheritance or another expected lump sum.
To manage cashflow when income varies from year to year, as it often does for self-employed professionals.

Here is an illustrative example, not market data. Say you borrow a sum and split it between repayment and interest-only. Each month you pay interest on the whole loan, plus a capital instalment on the repayment slice only. At the end of the term, the interest-only capital is still owed, and your repayment strategy has to cover it.

Who can qualify, and what do lenders check?

Qualifying means meeting the lender's standard affordability and credit checks, as well as providing a viable, documented plan to clear the interest-only slice at the end of the term. Lenders also look at whether you could afford any change in payments over time, not just today's figure.

Acceptable repayment vehicles vary by lender. Common examples include savings, investments, the proceeds of selling the property, or pension and lifetime products. A hope that house prices will rise is not a plan. Under the FCA's rules, speculative strategies must not be accepted, and lenders should review the strategy during the term.

Before you apply, gather:

Income evidence: payslips, or accounts and tax calculations if you are self-employed.
Bank statements covering the period your lender asks for.
Statements and recent valuations for any investment, savings plan or pension you intend to rely on.
Photo ID and proof of address.

Pro Tip: Ask each lender, before applying, which repayment vehicles it accepts and how often it will ask for evidence. Criteria differ between lenders, so one lender's answer is never a rule for the market.

How do UK rules and FCA guidance affect part interest-only mortgages?

The regulator shapes how these loans are underwritten, documented and managed. The key points are:

Lenders may only enter into an interest-only mortgage if they hold evidence that the repayment strategy has the potential to repay the capital.
Firms are expected to have policies for managing interest-only customers and to consider realistic options before maturity, such as switching to repayment, extending the term or accepting overpayments.
The offer document must include an illustration that states the interest-only element and reminds you to monitor your repayment vehicle.
If your strategy underperforms, the lender will expect you to cover any shortfall. Repossession is a last resort after fair treatment and review.

The FCA's guidance on this topic, FG13/7, is the document to read if you want the regulator's own wording on how firms should treat interest-only customers at risk of being unable to repay.

Regulatory point: MCOB 11.6 requires evidence that a repayment strategy can repay the capital, and it forbids speculative plans for interest-only lending.

In practice, this means your repayment plan is part of the lending decision, not a formality you complete afterwards. For a deeper look at the interest-only side of the rules, see our guide to interest-only mortgages under FCA rules.

Can you combine interest-only, repayment, offset and remortgaging?

Yes, within the limits each lender sets. These features interact in specific ways:

Offset facility: linking savings or a current account to the mortgage reduces the balance on which interest is charged. It lowers interest, but it does not remove the capital obligation on the interest-only slice.
Switching between slices: some lenders let you move part of the loan from interest-only to repayment, or the reverse. Expect an affordability reassessment and fresh paperwork either way.
Remortgaging: moving to a new lender, or a new product with your existing lender, can reset the structure. A remortgage involves a new application and checks. A product transfer or rate switch with your current lender is a different process with different checks.
Extending the term: this lowers the monthly payment on the repayment slice but costs more interest overall.

A caution on adding unsecured debts to a mortgage: consolidating credit cards or loans into your home loan can lower the monthly figure, but it spreads the debt over a longer term and puts your home at risk for debts that were previously unsecured. Advisers weigh that trade-off carefully.

One further point: part-and-part mortgages are generally not eligible for government-backed mortgage guarantee schemes, which are typically restricted to capital repayment mortgages. Check the scheme's current criteria before you plan around one.

What happens if your repayment strategy fails?

You remain contractually responsible for repaying the full capital at the end of the term. Lenders are not obliged to refinance if your plan falls short, which is why early action matters.

The realistic options at maturity, roughly in the order borrowers explore them, are:

Remortgage the outstanding balance onto a repayment product, if you pass the lender's affordability checks.
Extend the term, where the lender agrees, to spread the balance over more years.
Make part repayments or overpayments from savings, bonuses or a partial lump sum.
Use a specialist follow-on product where one suits your age and circumstances.
Sell the property and repay the capital from the proceeds.

Practitioner guidance also notes that lenders regularly review whether strategies remain on track during the term, so finding a shortfall early gives you more room to act.

Pro Tip: If you are struggling, speak to your lender as soon as possible. MoneyHelper notes that discussing options does not automatically appear on your credit file, while missed payments without agreement will.

How do you check whether a part and part mortgage is right for you?

Start with evidence, then questions. Pulling the paperwork together first shows you quickly whether the numbers hold up.

Documents to prepare:

Payslips, or accounts and tax calculations if you are self-employed.
Bank statements and ID.
Details and performance history of any repayment vehicle.
Proof of future income, such as contracts or projections, where your income is expected to change.

Questions to put to a lender or adviser:

Which repayment vehicles do you accept, and how often will you ask for updates?
What fees apply if I switch part of the loan between repayment and interest-only?
Are there early repayment charges on either slice?
How would a rise in rates affect my affordability at the end of any fixed period?

Regulated advice is particularly useful when income is complex. Our model is to provide a dedicated adviser from start to finish, so the person who understands your income also handles the lender conversations.

What are the typical scenarios and benefits for professionals?

Professionals with uneven or back-loaded earnings are the people this structure tends to suit. The benefit is flexibility on the monthly payment, balanced against a firm obligation to clear the interest-only slice later.

Common scenarios include:

Bonus-heavy earners: a banker or lawyer whose pay arrives largely as an annual bonus may want a lower contractual payment, with bonuses used for planned lump sums.
Partners expecting a payout: someone expecting a share of a practice, a vesting award or a business sale may set up an interest-only slice with that event as the documented plan.
Property owners planning to downsize: if you intend to sell the property to repay the interest-only slice, some lenders may consider it as a strategy, subject to their criteria and to your circumstances.
Mid-career cashflow pinch: during years of school fees or a business build-out, a smaller payment can ease pressure, with a plan to rebalance toward repayment later.

The key discipline is honesty about the future. Known changes in circumstances, such as a planned career break or a likely drop in income, belong in the application and in your plan, never left out. A lender who accepts a strategy built on accurate facts is far more likely to remain supportive if circumstances shift.

None of this guarantees acceptance. Each lender sets its own criteria, and what one accepts another may decline.

How does a part and part mortgage differ from other mortgage structures?

The differences come down to what happens to the capital and what the lender asks of you.

Full repayment is the simplest structure. Every monthly payment covers interest and a slice of capital, so the balance falls to zero by the end of the term. Monthly payments are higher, but you need no separate repayment vehicle, and you generally do not face the end-of-term question.

Pure interest-only means every payment covers interest alone. The full loan stays outstanding until the end of the term, so the lender expects a documented strategy for the entire balance. That tends to demand a larger and more clearly evidenced vehicle than a part-and-part loan does.

Part and part sits between the two. Because only a portion is interest-only, the repayment strategy has to cover a smaller sum, and the capital falls over time on the repayment slice. That can make the strategy easier to evidence and the end-of-term position less exposed.

Other points of difference:

Eligibility for government-backed guarantee schemes can differ, as noted above.
Switching between slices usually triggers a new affordability check.
Buy-to-let borrowers often use interest-only lending as a standard structure, with different lender criteria from residential loans. Our buy-to-let mortgage advice covers that route.

None of these structures is better in the abstract. The right one depends on your income pattern, your plan for the capital and your appetite for end-of-term risk.

How does complex income affect a part and part mortgage application?

Complex income changes the paperwork more than the principle. The lender still tests affordability and the repayment strategy, but it needs more evidence to be comfortable with both.

If you are self-employed, a lender will typically want several years of accounts or tax calculations, and it may average your income or use the most recent year, depending on its criteria. Directors may be assessed on salary and dividends, or on salary and retained profit, again depending on the lender. Contractors and people on fixed-term contracts face their own tests, which our guide to fixed term contract mortgages explains.

Bonus and commission income is often counted at a reduced proportion, and the proportion differs between lenders. Foreign nationals may face additional checks on residency and immigration status, covered in our foreign national mortgage guide.

Complex income also affects the repayment strategy itself. If your plan relies on a bonus, a business sale or investment returns, the lender will want to see why that source is realistic rather than speculative. A track record, a contract or a valuation helps; a hope does not.

Where you can, do three things before applying:

Assemble the full document set so the lender sees a coherent picture the first time.
Match each document to the lender's stated income rules, not a generic checklist.
Disclose known upcoming changes to income or outgoings.

Because criteria differ so much, matching your profile to the right lender often decides the outcome, and that is where adviser-led support earns its place.

What do successful part and part arrangements look like?

We do not publish client case files, so the following are illustrative scenarios, not real clients, and no outcome is implied for your own application.

Scenario one: the bonus-led professional. A borrower earns a modest base salary and a large annual bonus. They split the loan so the repayment slice fits comfortably within the base salary, while the interest-only slice carries a documented plan: each year, part of the bonus goes into a named investment account earmarked for the capital. The lender sees the plan, the account statements and a conservative growth assumption, and reviews it periodically.

Illustrated salary and bonus repayment pathways

Scenario two: the planned downsizer. A homeowner keeps a smaller interest-only slice, with the documented plan to sell and move to a cheaper property before the end of the term. The lender considers the equity in the home and the borrower's circumstances. The plan works only if it is realistic and revisited regularly.

Scenario three: the self-employed director. A director with variable profits keeps the repayment slice low enough to pass affordability on averaged income. The interest-only slice is backed by pension and savings, with annual statements to evidence progress.

What these arrangements share matters more than their details:

A repayment strategy that is specific and evidenced rather than speculative.
A split sized to affordable monthly payments.
Regular review of the vehicle, with a plan to rebalance if it falls behind.

Success here means a plan that stays credible over the whole term, not simply one that secures an offer.

How does protection advice fit with part and part mortgage planning?

A part-and-part mortgage depends on a plan holding up for many years, and protection helps keep the plan intact if your circumstances change. Protection cover is a separate decision from the mortgage, and advice should cover both.

The main types, and how they relate to the loan:

Life insurance pays out on death. With a mortgage that has an interest-only slice, a policy can help your family clear the debt rather than face a sale.
Income protection replaces part of your income if illness or injury stops you working. That helps keep both slices of the mortgage paid.
Family income benefit pays a regular income to your family if you die during the policy term.
Critical illness cover pays a lump sum on diagnosis of a listed serious condition, which could ease the strain on repayments.

For self-employed professionals, who often lack employer sick pay, income protection deserves particular thought. For anyone relying on an investment or pension to clear the interest-only slice, consider what happens to those contributions if you cannot work.

Protection is not a lender requirement for a part-and-part mortgage, but it is part of sensible planning, and we cover it as part of our protection advice. The right level of cover depends on your dependants, your existing benefits and your budget, and policies carry exclusions that you should read carefully.

What fees and costs should you expect?

Costs for a part-and-part mortgage broadly match those for other mortgages, plus any extra friction from the interest-only element. Look at the total cost, not just the headline rate.

Typical cost areas include:

Adviser or broker fees. We set our fees out in advance. Our purchase mortgage service is £495 one-off and our remortgage service is £195 one-off. We may also receive commission from lenders, and we explain how we are paid before you commit.
Lender product fees. These vary by product and can be added to the loan, which increases the interest you pay.
Valuation and legal fees. Some products include free valuations or legal work, others do not.
Early repayment charges. Check whether they apply to both slices, and what they cost if you overpay or switch.
Switching costs. Moving part of the loan between interest-only and repayment may involve fees or a fresh affordability assessment.

Interest costs deserve a mention. On the interest-only slice the balance does not fall, so you keep paying interest on the full slice for the whole term. Over a long term that can add up to more total interest than a full repayment loan of the same size, even though monthly payments are lower.

Ask every lender or adviser for a written breakdown of all fees and the total amount payable. Fees on the interest-only slice, and the cost of ending the plan early, are the points most often overlooked.

How can Haven Mark Advisers help with a part and part mortgage?

We provide regulated mortgage advice, match you to lenders whose criteria suit your circumstances, and assign one dedicated adviser from first call to offer. That adviser understands your income and your repayment plan, so you are not repeating yourself to different people.

Haven Mark Advisers

What to expect from us:

An initial call to understand your income, your plans and how you intend to clear any interest-only slice.
A document list tailored to your situation, particularly where income is complex or non-standard.
Help presenting your repayment strategy clearly to the lender.
Fees agreed upfront, explained on our fees page.

We cannot guarantee eligibility, acceptance, borrowing amounts or rates, and any outcome depends on your circumstances and the lender's criteria. Your home may be repossessed if you do not keep up repayments on your mortgage. If you would like to talk it through, request regulated advice and we will take it from there.

This article is general information, not a substitute for advice from a qualified financial advisor. Consult a qualified financial professional about your own circumstances before acting on anything here.

FAQ

Is it worth getting an interest-only mortgage?

It can be, but only if you have a credible plan to repay the capital at the end of the term. Lower monthly payments come with the obligation to clear the full interest-only balance later, and lenders must see evidence of a viable strategy before they lend.

Is 3.75% a good mortgage rate?

Whether a rate is good depends on the date, the product type, your deposit and your circumstances, so no single figure is good or bad for everyone. Compare the rate alongside fees and the total amount payable, and check current market rates with an adviser before deciding.

What are the four types of mortgages?

The terms vary, but mortgages can be grouped by repayment structure and rate type, such as repayment, interest-only, part and part, and fixed or variable rate options. Our guide to interest-only mortgages explains the structure side in more detail.

Can I get a 250k mortgage on a 50k salary?

It depends on the lender's affordability assessment, your deposit, your debts and your outgoings, and nobody can promise a figure. Lenders use different income multiples and test whether you could afford payments under their own criteria, so speak to an adviser about your specific position.