Every June a particular dread arrives in my inbox, and it always wears a friendly face. A wedding invitation. A school letter listing the cost of the new uniform, the trip to France, the gym kit her old one no longer fits. A group chat plotting a long weekend in Lisbon, accommodation already booked, deposit due Friday. None of it is an emergency. All of it lands at once.
The trap with summer spending isn't that it's enormous. It's that it's predictable and we treat it as a surprise anyway. We know weddings cluster between May and September. We know children grow out of shoes by August. We know that the car insurance renews when it renews, whether or not we feel ready. Yet the money tends to come from the same place every time: the current account on the day the bill arrives, followed by a quiet shuffle of the credit card and a promise to "sort it out next month."
What a sinking fund actually is (and why the name is awful)
A sinking fund is money you set aside in advance for a known, irregular expense — split into small monthly amounts so the cost never hits in one lump. The term comes from corporate accounting, where companies "sink" money into a reserve to pay off a debt or replace equipment. It sounds like something a Victorian bank manager would say, which is a shame, because the idea is the most practical thing in personal finance.
Here's the distinction that matters. An emergency fund covers the things you cannot predict — the boiler, the redundancy, the dental bill that arrives with a sharp intake of breath. A sinking fund covers the things you absolutely can predict but keep pretending you can't. Christmas is not an emergency. It happens on the 25th of December, the same date it has occupied your entire life. The car's MOT is not a shock. Your sister's hen weekend, announced eight months out, is not a bolt from the blue.
Treat predictable costs as emergencies and you drain the fund meant for real ones. That's the whole argument for keeping them separate.
Find the lumps before they find you
Start with a year, not a month. Pull up your bank statements from the last twelve months — most banking apps let you scroll back or export a CSV — and hunt for the charges that don't appear every month but reliably appear. The annual ones hide best: the Amazon Prime renewal you forgot auto-renews, the £79 you pay once a year for car breakdown cover, the insurance that quietly jumped at renewal.
A starter list of categories worth their own fund:
- Christmas and December birthdays — gifts, food, the train home, all of it
- Car ownership beyond fuel: insurance renewal, MOT, servicing, the tyre that will eventually go
- Annual subscriptions bundled into one line so they stop ambushing you one by one
- Holidays and weekends away, including the friend-of-a-friend's destination wedding you haven't agreed to yet but secretly know you will
- Back-to-school: uniform, shoes, the laptop, the trips that always cost more than the letter implies
- Birthdays and weddings you're invited to — the gifts, the outfit, the hotel, the round at the bar
The point of writing it down is not tidiness. It's that the total is almost always bigger than the number living in your head. People budget for the holiday and forget the kennels for the dog, the airport parking, the spending money, the new swimsuit. A sinking fund forces you to cost the whole thing once, calmly, in February — rather than discovering it in pieces in July with your card already out.
The maths is dull, which is exactly why it works
Take a wedding you're a guest at next August. Say the gift is £80, a dress and shoes you don't already own come to £120, the hotel for one night is £130, and travel is £60. That's £390, and you've got six months. Divide it: £65 a month, set aside from February, and the wedding costs you nothing in August. It was already paid for, quietly, while you weren't looking.
Do the same for the categories that recur every year and you can divide by twelve. A £1,200 annual budget for Christmas, car costs, and holidays combined becomes £100 a month — a figure you can actually plan around, instead of a £1,200 wall you hit in a single season. The trick is that nothing about the total changed. You're spending the same money. You've just stopped letting it arrive as a crisis.
One honest caveat: this only works if you genuinely have the monthly room. If £100 a month isn't there, no clever account structure conjures it — that's a different conversation about income and fixed costs, and pretending a sinking fund solves it would be dishonest. But for a great many women the money does exist; it just leaks invisibly across the month and reassembles itself, painfully, as a lump.
Where to keep it — and why your current account is the wrong answer
Money you can see in your spending account is money you will spend. This isn't a character flaw; it's how current accounts are designed to feel. So the fund needs to live somewhere with a small amount of friction — close enough to reach in a day, far enough that you won't dip in for a Friday takeaway.
A high-yield savings account is the obvious home, and there are genuinely good options. In the UK, Monzo and Starling both let you carve money into separate "Pots" or "Spaces" — a labelled jar for Christmas, another for the car, another for holidays — which is the single most useful feature for this whole method, because each fund is visibly its own thing. In the US, Ally Bank's "buckets" do the same inside one savings account, and Marcus by Goldman Sachs pays a competitive APY on a straightforward online saver. Rates move constantly, so check the live AER or APY before you commit rather than trusting a number from a year-old article; easy-access savings in 2026 have generally sat somewhere in the 3.5–4.5% range, but that is a moving target, not a promise.
Open one account, then use its sub-pots for each category. Don't open eleven separate accounts at eleven banks — you'll lose track, miss the interest, and quietly abandon the whole system by March. One account, many labelled jars. The labels matter more than people expect; "Holiday – Greece August" is harder to raid than an anonymous balance, because spending it means admitting out loud you're taking the Greece money.
Automate it, then forget it exists
The single move that separates people who do this from people who mean to is the standing order. Set up an automatic transfer for the day after payday — not the 1st, not the 28th, the day your salary actually lands plus one. Willpower is a terrible savings strategy because it asks you to choose, correctly, every single month for years. Automation asks you to choose once.
If your salary varies — freelance, commission, shifts that change — fix the transfer at the lowest amount you can always cover, then top up by hand in the months you earn more. A reliable £40 beats an ambitious £150 you cancel every other month because it left you short. Consistency is the entire engine here. A small amount that never stops outperforms a heroic amount that stutters.
Once it's running, check it quarterly, not daily. The whole appeal of a sinking fund is that it removes a recurring decision from your life. Watching the balance every morning re-inserts the decision you just paid to delete.
When the plan meets real life
It won't be perfect, and that's fine. You'll under-budget the first Christmas because you always do; nudge the monthly figure up in January and move on. A category will appear that you never funded — a friend's surprise 40th in Mallorca, say — and you'll borrow from the holiday pot to cover it. That's not failure. That's a fund doing its job, which is to give you money to move around rather than a panic to manage.
The version of you in November will think about this far less than the version of you reading it now does. She'll have a labelled jar with £300 in it that she barely remembers building, and the gifts will simply get bought. No card juggling, no January regret, no quiet maths at 1am about whether the payment will clear. Boring, completely unglamorous, and the closest thing to a cheat code that ordinary money management offers.
Start with one fund. Pick the next big lump on your horizon — it's probably summer — work out the monthly figure, and set the standing order before you close this tab. The interest you earn is a nice extra. The thing you're really buying is the absence of dread next June.