Where should I put my next £1,000?
For higher-rate taxpayers focused on retirement, pension contributions via salary sacrifice are usually the most tax-efficient option. A Stocks and Shares ISA tends to suit those who want penalty-free access. Mortgage overpayment can make sense when interest rates are high or ISA and pension allowances are already used.
Check the basics first
Before optimising the next £1,000, it's worth covering the foundations. A good rule of thumb is 3 to 6 months of essential spending in an easy-access account, plus enough pension contribution to capture the full employer match. Most people also look to clear expensive debt before directing money toward investing or overpaying a low-rate mortgage.
For more on this, see our emergency fund quick read.
When a pension tends to win
Salary sacrifice avoids income tax and employee National Insurance on that slice of pay. So £1,000 from take-home can become a larger gross pension contribution. The pot grows largely tax-free until retirement.
This route is generally most efficient for 40% taxpayers focused on long-term goals who aren't up against the tapered annual allowance. Pension contributions are especially valuable between £100,000 and £125,140, where they can help reclaim the personal allowance. Our 60% tax trap piece explains why.
When an ISA tends to win
There's no tax relief on the way in, but gains and withdrawals are tax-free. That flexibility matters for a house deposit, career break, or simply keeping options open.
The ISA allowance is £20,000 in 2025/26. For money that might be needed within five to ten years, an ISA is a common choice. For the broader pension vs ISA comparison, see pension or ISA.
When mortgage overpayment tends to win
Overpaying gives a return equal to the interest avoided, with no market risk. At 5% or more, that can beat cash and sometimes rival investing after tax, particularly once tax wrappers are full.
When mortgage rates are under 3% and ISA or pension allowance remains, investing tends to come out ahead on long-term maths. The money is also tied up in the property. For the wider trade-off, see mortgage vs invest.
