Should you clear your debts before retiring, or keep cheap borrowing?
The arithmetic is straightforward: clear debt costing more than your portfolio is likely to earn after tax, and consider keeping debt costing less. What complicates it is that a mortgage payment in retirement is a fixed claim on a variable income, and that risk does not appear anywhere in the interest rate comparison.
- The rate test: clear anything costing more than your expected after-tax return.
- The flexibility test: a fixed payment against a variable income is a risk the rate does not price.
- The tax-free cash question: using the pension lump sum to clear a mortgage removes a fixed claim permanently.
- What not to clear: an interest-free or very low-rate balance with a defined end date.
Tom had eleven years left on a mortgage at 2.1% and every spreadsheet said keep it. He cleared it anyway with part of his tax-free cash, and I think he was right for reasons the spreadsheet could not show.
01 The arithmetic, which is the easy part
Debt costing more than your portfolio is likely to earn after tax should be cleared. Credit cards, unsecured loans and anything above about 6% fall into this category comfortably, and repaying them is a guaranteed return equal to the interest rate.
Below that the comparison is genuinely close. A mortgage at 2.1% against a portfolio expected to return 5% net looks like a clear case for keeping the debt, and on expected values it is.
What the comparison omits is certainty. The 2.1% is contractual and the 5% is an expectation with a wide distribution, and swapping a certain cost for an uncertain return is not the same trade in retirement as it is at 40.
Shows: what keeping a debt costs against what the same money might earn invested. Ignores: the certainty of the interest cost against the uncertainty of the return, tax on the return, and cash-flow risk.
On the defaults above, the worked example shows £27,209. Keeping the debt is ahead by £27,209 on expected values — before considering that the interest is certain and the return is not.
Source: Bank Rate and how it works
02 Why a fixed payment is different in retirement
In work, a mortgage payment is met from a salary that arrives regardless of markets. In retirement it is met from a portfolio, and a fixed monthly claim against a variable income is exactly the structure that forces selling into a fall.
It also removes the flexibility that makes a drawdown plan survivable. Cutting the withdrawal after a bad year is only possible where the spending is discretionary, and a mortgage payment is not.
So the question is not only whether the rate is below the expected return. It is whether the payment is small enough that the plan retains the flexibility it needs.
There is a second effect that only shows up in a bad decade. A household forced to keep withdrawing at the same level through a market fall sells more units at lower prices, and the mortgage payment is the part of the withdrawal that cannot be reduced. Clearing it converts a fixed claim into a discretionary one, which is the single change that makes a flexible withdrawal rule possible at all.
Source: Plan your retirement income
03 Using tax-free cash to clear a mortgage
Tax-free cash is the cheapest money available for this, because it costs no Income Tax. Clearing a £60,000 mortgage from the pension commencement lump sum uses £60,000 of pot; clearing it from taxable drawdown at 40% would take £100,000.
The cost is the pot's future growth on that money, and the lump sum allowance it consumes for anyone approaching the £268,275 cap. For most households neither is binding, and the transaction is straightforward.
It also has to be sized against the rest of the plan. Using the whole lump sum on a mortgage leaves nothing for the early retirement years that the lump sum often funds, so the sequencing matters more than the decision.
04 What to keep
An interest-free balance with a defined end date is worth keeping, because clearing it early has a return of exactly zero. The same applies to a genuinely low fixed rate with a short remaining term where the payment is comfortably affordable.
A student loan is a separate case: it is repaid as a percentage of income above a threshold and written off after a set period, so for many retirees it costs nothing at all once earnings stop. Clearing it voluntarily is usually a poor use of capital.
And an offset arrangement, where savings reduce the interest without repaying the capital, can give most of the benefit of clearing the debt while keeping the money available.
Source: Repaying your student loan
05 The order to do it in
Clear anything above about 6% immediately, from whatever source. Then look at the mortgage: if it will run past your retirement date, decide whether the payment is small enough to be absorbed by discretionary spending, and clear it if not.
Fund that from tax-free cash rather than from taxable withdrawals, and size the lump sum use against whatever else it was going to do. Then keep the interest-free and written-off debt exactly where it is.
Review it once when the retirement date is set, and once again if rates move materially. This is not an annual decision.
One sequencing point matters more than the rest. If tax-free cash is going to clear the mortgage, take it before starting taxable withdrawals rather than after, because the lump sum can be taken without triggering the money purchase annual allowance and a taxable withdrawal cannot. Doing it in the wrong order costs contribution room for anyone still earning.
The spreadsheet said keep the 2.1% mortgage and I still think clearing it was right, which is worth explaining rather than hiding. In work, a mortgage payment comes out of a salary that arrives whatever markets do. In retirement it comes out of a portfolio, and a fixed claim against a variable income is exactly what stops you cutting withdrawals in a bad year — the one move that most reliably saves a drawdown plan. Clear the expensive debt on arithmetic. Clear the cheap mortgage if the payment is big enough to take your flexibility away.
FAQ
Should I clear my mortgage before retiring?
If the payment is large enough that you could not cut your withdrawals in a bad year, yes — flexibility is worth more than the rate difference. If it is small and comfortably absorbed by discretionary spending, the arithmetic favours keeping a genuinely cheap rate.
Is tax-free cash the right money to use?
It is the cheapest, because it costs no Income Tax. Clearing £60,000 of mortgage from the lump sum uses £60,000 of pot, where funding it from taxable drawdown at 40% would take £100,000.
Should I repay my student loan early?
Usually not. It is repaid as a percentage of income above a threshold and written off after a set period, so once earnings stop it may cost nothing at all. Voluntary repayment converts a contingent liability into a certain payment.
What about interest-free credit?
Keep it and pay it on schedule. Clearing an interest-free balance early has a return of exactly zero, and the money is more useful available.
Sources
Regulator references
- Bank Rate and how it works · Bank of England · 2025The policy rate that drives the mortgage and cash comparisons here.Last verified: 2026-09-07
- Plan your retirement income · GOV.UK · 2025The government's own sequence for turning pension pots into income.Last verified: 2026-09-07
- Tax on your private pension contributions · GOV.UK · 2025The relief, allowance and charge framework the whole post sits inside.Last verified: 2026-09-07
- Repaying your student loan · GOV.UK · 2025The plan types, thresholds and write-off dates the arithmetic uses.Last verified: 2026-09-07
- MoneyHelper: pensions and retirement · MoneyHelper · 2025The government-backed guidance service, cited for the free-guidance route.Last verified: 2026-09-07
Calculator unit tests · the assertions this page's worked example is checked against, and their last result
Changelog
- 2026-09-07 — initial publish (new format)
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Jordan Reeves
Founder of Talk Through Wealth. A software engineer for over a decade before turning to retirement planning, Jordan built the projection engine after watching family members get fragmented, country-by-country advice that never reconciled. He writes about retirement the way the engine computes it: month-by-month, lifetime-long, and skeptical of any rule of thumb that hasn't been run through the math.