Comparison Guide · Updated July 2026
Part-and-Part Mortgage vs Full Repayment Mortgage 2026
A part-and-part mortgage splits your loan into an interest-only portion and a repayment portion, lowering your monthly payment but leaving a lump sum outstanding at the end of the term. A full repayment mortgage clears the entire balance by the end of the term through higher monthly payments. Understanding the trade-off between monthly cost and end-of-term risk is essential before choosing either structure in 2026.
TL;DR
- Part-and-part mortgage: Lower monthly payment; lump sum still owed at term end on the interest-only portion; needs a repayment vehicle
- Full repayment mortgage: Higher monthly payment; loan fully cleared by term end; no end-of-term shortfall risk
Side-by-Side Comparison
| Feature | Part-and-Part Mortgage | Full Repayment Mortgage |
|---|---|---|
| Monthly payment | Lower (interest-only on part of balance) | Higher (capital + interest on full balance) |
| Balance at end of term | Lump sum owed on interest-only portion | Zero — fully cleared |
| Repayment vehicle required | Yes, for the interest-only portion | No |
| Total interest paid over term | Higher than full repayment | Lower |
| Maximum LTV on interest-only portion | Often capped lower (e.g. 50–75%) | Not applicable |
| Best for | Borrowers with a credible lump-sum plan wanting lower payments now | Borrowers who want the mortgage cleared with certainty |
How a Part-and-Part Mortgage Works
A part-and-part mortgage divides the loan into two components with the same lender, on the same rate or two separate rates depending on the product: an interest-only portion, where your monthly payment covers only interest and the capital never reduces, and a repayment portion, where your payment covers both interest and capital, gradually clearing that part of the debt. Lenders require a credible plan — a "repayment vehicle" — to clear the interest-only portion by the end of the term, such as an ISA, pension lump sum, other investments, or a firm plan to sell the property or downsize.
How a Full Repayment Mortgage Works
A full repayment mortgage applies the standard capital-and-interest structure to the entire loan. Each monthly payment is calculated so that, by the final payment, the whole balance is cleared to zero (assuming no missed payments or rate changes affecting the amortisation schedule). This is the default and most common mortgage structure for owner-occupied residential properties in the UK, and it carries no end-of-term balloon-payment risk.
Worked Example — £250,000 Mortgage, 25-Year Term at 4.5%
| Structure | Approx. Monthly Payment | Balance Owed at End of Term |
|---|---|---|
| Full repayment (£250,000) | £1,389 | £0 |
| Part-and-part (£100,000 interest-only + £150,000 repayment) | £1,208 | £100,000 (interest-only portion) |
Illustrative example only, based on standard amortisation maths at a flat 4.5% rate over 25 years. Actual figures depend on your lender, rate and product.
Which Should You Choose?
A full repayment mortgage is the safer default for most owner-occupiers, since it removes any risk of a shortfall at the end of the term. A part-and-part mortgage can suit borrowers who genuinely have a credible, evidenced plan to clear a lump sum — for example an expected inheritance, a maturing investment, a pension tax-free cash entitlement, or a firm intention to downsize — and who want lower monthly outgoings in the meantime. Lenders will scrutinise the repayment-vehicle evidence carefully, and borrowers should stress-test whether the plan would still work if the investment underperformed.