Remortgage to Interest-Only

Why Switch From Repayment to Interest-Only?

Common reasons to remortgage from repayment to interest-only include:

• Short-term cash flow relief — redundancy, divorce, business setup, medical costs, or school fees can all create temporary pressure on monthly cash flow
• Nearing retirement with a clear repayment plan — if you have a pension lump sum, endowment, or investment portfolio earmarked for the mortgage, interest-only keeps monthly costs low while the vehicle matures
• Plan to downsize in future — if you expect to sell the property and downsize in 10-15 years, interest-only during that period preserves cash flow and the eventual sale clears the debt
• Investment strategy — some borrowers consciously prefer to keep the mortgage large and invest the monthly cash flow difference, targeting a return higher than the mortgage rate
• Self-employed with lumpy income — interest-only smooths payments, with capital repayments made via annual overpayments from profits

A switch to interest-only is not usually a long-term solution unless you have a robust repayment plan. Lenders will want to see evidence of that plan and may review it annually.

Lender Criteria for Interest-Only Remortgages

Interest-only lenders apply tougher criteria than repayment lenders. Typical 2026 requirements:

Lender	Max LTV	Minimum Income	Notes
Santander	75%	£50,000 sole / £75,000 joint	Accepts sale of property with £150k+ equity
Halifax	75%	£75,000 sole	Wide range of vehicles accepted
Barclays	75%	£75,000 combined	Will accept part-and-part
Metro Bank	75%	£75,000 sole / £100,000 joint	Minimum £300k equity for sale-based plans
Nationwide	60%	£50,000 sole	Strict on vehicle evidence
Coventry BS	65%	Case-by-case	Flexible, broker-friendly

Most lenders cap interest-only at 75% LTV, with Nationwide and Coventry stricter at 60-65%. Minimum income thresholds are designed to give confidence that the borrower can maintain the repayment vehicle alongside the mortgage.

Repayment Vehicles Accepted

You must nominate a repayment vehicle — a plan for clearing the capital at the end of the term. Accepted vehicles generally include:

• Stocks and shares ISA — current value and/or regular contributions, projected at a conservative growth rate (typically 3-5% net)
• Pension — typically the 25% tax-free lump sum, backed by a recent annual statement and with a retirement date before mortgage maturity
• Sale of mortgaged property — requires minimum projected equity (often £150,000-£300,000 depending on lender) and suitable property value
• Sale of second property or buy-to-let — you need documented ownership, equity, and a marketability case
• Endowment policy — mostly legacy from the 1990s, still acceptable if projections are sufficient
• Overpayments from bonuses/dividends — accepted by some specialist lenders if the income pattern is documented

Lenders typically discount the projected value of investment and pension vehicles to build in a margin of safety. For example, Santander might count 80% of projected ISA value, Halifax 75%.

Age at End of Term

Age at maturity is a key constraint. On a 20-year term starting at age 55, you would be 75 at maturity, which is acceptable to most interest-only lenders. On a 30-year term at the same starting age, maturity at 85 is accepted only by RIO lenders or specialist over-55 lenders.

Typical age-at-maturity limits for interest-only:

• Halifax: 80
• Santander: 75
• Barclays: 70-80 depending on product
• Nationwide: 75
• Metro Bank: 75
• Leeds BS (RIO): no maximum
• Hodge, Livemore, Pure Retirement (RIO): no maximum

Borrowers over 55 who exceed standard age limits should look at retirement interest-only (RIO) mortgages. These have no fixed end date and run for life, with the loan repaid when you die, sell, or move into care. RIO rates in 2026 are typically 6.00-6.75%.

Part-and-Part as an Alternative

If you do not meet full interest-only criteria, a part-and-part mortgage is a useful compromise. For example, on a £250,000 mortgage:

• £150,000 on repayment (25 years) — £877 a month at 5%
• £100,000 on interest-only — £417 a month at 5%
• Total monthly: £1,294 — around £167 less than full repayment
• Capital owed at end of term: £100,000 (needs repayment vehicle)

Part-and-part is accepted by most major UK lenders and can be a more realistic route if your income or LTV does not meet full interest-only criteria. It also reduces the repayment vehicle pressure because you only need to cover £100,000 rather than the full £250,000.

The Remortgage Process

A remortgage to interest-only follows the standard remortgage timeline, with additional evidence around the repayment vehicle:

1. Review your current mortgage — outstanding balance, ERC if any, end of current deal
2. Confirm eligibility — LTV, income, age at term end, repayment vehicle evidence
3. Gather documentation — payslips/accounts, bank statements, ID, pension or ISA statements, property valuation if using sale
4. Apply for decision in principle — typically issued within 24-48 hours
5. Submit full application — with full repayment vehicle evidence
6. Valuation and underwriting — 1-3 weeks
7. Mortgage offer and completion — 2-4 weeks from offer to completion

The whole process typically takes 6-10 weeks. A whole-of-market broker is particularly valuable for interest-only because criteria vary significantly between lenders and not all are published openly.

Alternatives to a Full Interest-Only Switch

If interest-only criteria feel tight, several alternatives can achieve similar payment relief:

• Extend the term — increasing a 15-year remaining term to 25 years on a £200,000 mortgage at 5% reduces monthly payments from £1,581 to £1,169 — a saving of £412 a month, without changing product type. The trade-off: you pay more total interest because the loan runs longer
• Part-and-part — half the loan on repayment, half on interest-only, gives a middle ground with lower monthly cost and a smaller capital balance to clear at maturity
• Payment holiday — most lenders allow short payment holidays in hardship cases, though these usually add to the balance. Not a long-term solution
• Switch to a tracker with low ERC — if you expect your financial situation to improve within 2 years, a short-term tracker buys flexibility without the complexity of interest-only
• Retirement interest-only (if 55+) — RIO mortgages have no fixed end date and much simpler criteria, though rates are higher (6.00-6.75% in 2026)

A broker can model these side-by-side against a full interest-only switch, showing the trade-offs in monthly cost, total interest, and end-of-term balance.

Tax Implications of Interest-Only Vehicles

The repayment vehicle choice has tax implications that can change the net cost of the strategy:

• Stocks and shares ISA — fully tax-free growth and withdrawals. The most tax-efficient mainstream vehicle. Annual contribution limit £20,000 (2026)
• Pension (25% tax-free lump sum) — growth is tax-free inside the pension. The 25% lump sum is tax-free on withdrawal (from age 55, rising to 57 from 2028). Beyond the 25%, further withdrawals are taxed at your marginal income tax rate
• General Investment Account (GIA) — taxed outside an ISA/pension wrapper. Gains above the annual capital gains tax allowance (£3,000 in 2026) are taxed at 18% or 24% depending on your income tax band
• Endowment policy — normally tax-free at maturity if the policy qualifies under HMRC rules (10+ year term, regular premiums)
• Property sale — if the mortgaged property is your main residence, any gain is covered by Principal Private Residence (PPR) relief and is tax-free. Sale of a buy-to-let or second property attracts capital gains tax

For higher-rate and additional-rate taxpayers, using an ISA as the repayment vehicle is usually the most efficient — the tax-free compounding over 15-25 years can comfortably outweigh the modest monthly saving from interest-only. A £250 a month ISA contribution over 25 years at 6% net growth would accumulate around £169,000, which can significantly reduce the capital balance owed at maturity.

Common Pitfalls When Switching to Interest-Only

Several traps catch out borrowers switching from repayment to interest-only:

Underestimating the capital problem — on a £250,000 interest-only mortgage, you still owe £250,000 at the end of the term. That is the equivalent of buying a house outright from savings. Without a credible vehicle, this is a life-changing sum to raise in your 60s or 70s.

Relying on property sale without a Plan B — if the housing market stagnates, your projected equity may not materialise. Lenders increasingly want evidence of a secondary plan.

Treating interest-only as "free money" — over 25 years, interest-only costs significantly more in total interest than repayment. The monthly relief is genuine, but the total cost must be weighed against the benefit.

Missing product transfer opportunities — some existing lenders allow a switch to interest-only through a product transfer without new underwriting, which can be faster and cheaper than a full remortgage. Ask your existing lender before going to market.

Ignoring early repayment charges — if your existing deal has an ERC, the cost of breaking it to switch to interest-only may be significant. Wait until the deal end if possible.