How to set up a sinking fund for family expenses you can actually see coming

What a sinking fund actually is, and how it differs from an emergency fund

A sinking fund is money you save regularly for a cost you already know is coming, rather than one you hope never arrives. MoneyHelper, the government backed money guidance service, defines it as a pot you pay into for an expense on its way, whether a holiday or a recurring bill such as car insurance or an MOT (MoneyHelper, 2026).

An emergency fund protects you from shock, a job loss, a burst boiler. A sinking fund protects you from your own calendar. Most households build the emergency fund and let predictable costs land on a credit card instead, even when the household income is healthy.

How to work out what your sinking funds should actually cover

List every cost you can reasonably expect in the next twelve months that is not a monthly direct debit: car insurance and servicing, Christmas, a summer holiday, school trips, a boiler service. Add those up, then add roughly ten per cent for costs that come in higher than expected, as MoneyHelper also recommends, and divide by twelve.

A household expecting £600 for car costs, £800 for Christmas and birthdays, £1,800 for a summer holiday and £400 for a boiler service is looking at £3,600 a year, or £330 a month with the buffer added. Seeing that total in one place changes how it feels to pay for it.

Where the money should sit, and why that matters more once you earn more

The money belongs somewhere separate from everyday spending, typically an easy access savings account or a Cash ISA. Which one you choose carries a tax consequence most sinking fund guides skip entirely.

Every UK saver has a Personal Savings Allowance, the interest you can earn each year before tax. For 2026/27, basic rate taxpayers can earn £1,000 of savings interest tax free, higher rate taxpayers £500, and additional rate taxpayers, those earning over £125,140, get no allowance at all (Hargreaves Lansdown, 2026). Run several sinking funds totalling several thousand pounds, and that interest can tip over your allowance faster than expected. A Cash ISA shelters it entirely, whatever your tax band.

Why this catches out higher earners as much as anyone else

The absence of a sinking fund is rarely about how much a household earns. It is about whether there is a separate, named place for a cost that was always going to happen. The FCA's Financial Lives 2024 survey, published May 2025, found 21% of UK adults have less than £1,000 available for emergencies, and one in ten hold no cash savings at all.

Those figures describe the country as a whole, but the pattern holds at every income level. A household earning well into six figures can still find a car replacement or a run of school trips landing as a genuine problem, because the cost was never separated out. Higher earners often carry larger versions of the same costs, so the gap shows up as a bigger credit card bill rather than a smaller one.

From Lucy, co-founder of Welleness

The cost that used to catch me out every year was my car insurance renewal. I always knew it was coming, I just never got around to putting money aside for it, so it felt like an unplanned hit at exactly the wrong moment.

What changed things was ridiculously simple. I opened one extra savings account, named it after the thing it was for, and set up a standing order for the day after payday. The money was already there when the email landed.

A lot of women doing well financially still carry this particular stress, not because the money is not there, but because it was never separated out and given a job to do.

What you can do now

Open one separate savings account this week, name it after your next predictable cost such as car insurance or Christmas, and set up a standing order for the day after payday.

List every cost from the last twelve months that felt like a surprise, and add them up for a real annual figure rather than a guess.

If you hold more than a few thousand pounds across these pots as a higher or additional rate taxpayer, check whether a Cash ISA would shelter the interest from tax.

Frequently asked questions

What is the difference between a sinking fund and an emergency fund?

A sinking fund covers costs you already know are coming. An emergency fund covers what you cannot predict. Most households need both, emergency fund first.

How many sinking funds should I have?

As many as you have distinct predictable costs. Three to five pots, covering car costs, Christmas, holidays and home maintenance, usually cover the bulk of it.

Cash ISA or a normal savings account?

Either works within your Personal Savings Allowance. Once interest is likely to exceed £500 a year as a higher rate taxpayer, or any amount as an additional rate taxpayer, a Cash ISA avoids the tax question entirely.

What if I cannot afford to fund everything at once?

Start with whichever cost would otherwise end up on a credit card. Saving something is still progress, even if it takes a year to catch up.

Here is what one Welleness member said after completing her financial health check.

"WOW! I am blown away and actually really grateful. This landed at just the right time for me. I'm at an odd point, financially, definitely want to take more control, shitting myself about having taken a number of years out of investing in my pension and taking a hit to my income. So I'm really grateful to you for developing this because I think it is SO needed." Jude, Welleness user

If reading this has made you wonder what your own sinking funds should cover, our free financial health check takes less than five minutes and gives you a clear picture across six areas of your financial life. No judgement, no jargon, just clarity.

This post is for informational purposes only and does not constitute financial advice. For guidance specific to your situation, speak to a regulated financial adviser.