Steady It Savings
Sinking funds: how to save for the costs you know are coming
Some costs are not emergencies - they are just predictable. Christmas is not a surprise. Neither is the car's MOT or next summer's holiday. Sinking funds are the calm way to make those costs painless: small amounts set aside each month so the bill is already paid for when it lands. Here is how to build them without feeling like you are sacrificing anything.
By Chris Willman · Last reviewed · About a 7 minute read
The short version
- Sinking funds are for predictable-but-irregular costs: Christmas, the car, holidays, annual bills.
- Divide the yearly cost by twelve and save it monthly, so the bill is covered before it arrives.
- Keep three separate buckets: emergencies (surprises), sinking funds (known costs), and long-term wealth.
- Name each pot after its goal - a named pot gets raided far less than a generic 'savings' one.
What is a sinking fund and why does it work so well?
In short: In short: a sinking fund turns a nasty once-a-year bill into a calm monthly line.
A sinking fund is money you set aside monthly for a cost you know is coming, even if you do not know the exact date. Christmas costs roughly the same most years. The car MOT is annual. A holiday you are planning has a rough budget. Divide the expected cost by twelve and save that amount each month. When the bill arrives, the money is already there.
The difference between a sinking fund and ordinary saving is specificity. A sinking fund has a target, a purpose, and a monthly contribution that is sized to meet that target. It is not saving in general - it is saving for something specific, on a plan that ensures you get there.
The psychological benefit is as important as the financial one. Costs that used to feel like emergencies become non-events. The MOT bill lands and you transfer the money calmly because it was always set aside for exactly this. That shift - from financial shock to planned event - is what makes sinking funds one of the most underrated tools in personal finance.
Why should savings live in three separate buckets?
In short: In short: separating your savings by job protects each pot from raiding the wrong one.
Three distinct buckets do different jobs, and keeping them separate is what makes the system work.
- Emergency fund: genuine surprises - a job loss, a broken boiler, a medical cost. Money that must be available and untouched until a real emergency arrives.
- Sinking funds: predictable but irregular costs - Christmas, the MOT, the summer holiday, an annual insurance renewal. Money that is earmarked and scheduled.
- Long-term wealth: investing for the future - pension, ISA, long-term savings. Money that is not touched for years.
Keeping them separate prevents the emergency fund from being raided for a holiday, and prevents holiday saving from feeling like it is competing with security. When each bucket has one job, you always know which money is which.
In practice, this means at least two separate savings accounts beyond your current account - one for emergencies, one (or several named pots within one) for sinking funds. Most modern banks and savings apps make this easy.
Does naming a savings pot really make a difference?
In short: In short: a pot labelled 'Italy 2027' is far harder to raid than one labelled 'Savings'.
This is a well-documented effect in behavioural finance: named savings pots are significantly harder to spend impulsively than generic ones. 'Savings' is abstract. 'Christmas 2026' is specific. 'Car MOT fund' is specific. 'Italy 2027' is very specific.
When the pot has a name, dipping into it requires overriding a specific future plan, not just moving abstract money around. The psychological friction is real and useful. It does not make raiding the pot impossible, but it makes you pause and confront what you are doing - which is often enough to stop it.
If your bank does not support named pots, a simple spreadsheet tracking each sinking fund separately achieves a similar effect - the visibility of where each pound is assigned does the job.
How do you make sinking funds automatic?
In short: In short: set the transfer on day two of the month and never think about it again.
Set up automatic transfers on the second day of the month. Day one is often when salaries arrive - letting it land first avoids any timing issues with payroll. Day two, the transfers go: one for each sinking fund, each for the monthly fraction of its annual target.
This removes the monthly decision entirely. You do not have to remember, check the balance, or talk yourself into saving this month. The system runs in the background. Once the amounts are set correctly, sinking funds require almost no attention - which is exactly the point.
Review the amounts once a year - usually January, after you have seen what the previous year actually cost. Adjust any targets that were off, add any new sinking funds, and then leave it running again.
Frequently asked questions
What is a sinking fund?
Money you set aside monthly for a known future cost - like Christmas, a car service, or a holiday - by dividing the yearly amount by twelve. It turns predictable but irregular bills into a calm monthly habit rather than a nasty surprise.
What is the difference between a sinking fund and an emergency fund?
An emergency fund is for genuine surprises (a job loss, a broken boiler). A sinking fund is for costs you know are coming (Christmas, the MOT). Keeping them separate protects your emergency fund for real emergencies.
Written by Chris Willman, founder of Money Matrix Unplugged. This is financial education, not personal advice.