Sinking funds: how to stop yearly bills from wrecking a month
A sinking fund is money set aside a little at a time for a bill you know is coming but do not pay monthly: insurance, a renewal, a holiday, car repairs. Divide the bill by the months until it is due and reserve that amount each month, so the due date is a transfer rather than a shock.
Two ways to pace it
- Steady pace: divide the yearly bill by twelve and set that aside every month, all year, regardless of when the bill falls.
- Catch-up pace: divide what is still needed by the months left before the due date. Higher at first if you start late, then it settles into the steady pace after the first cycle.
A worked example
| Bill | Amount | Due | Steady pace | Catch-up pace from September |
|---|---|---|---|---|
| Car insurance | $1,140 | March | $95 / month | $190 / month for 6 months |
| Domain and hosting | $180 | January | $15 / month | $45 / month for 4 months |
| Holiday | $2,400 | July | $200 / month | $240 / month for 10 months |
| Combined | $310 / month | $475 / month |
Where the money lives
It does not need its own account. What matters is that it is not counted as spendable. Treat the set-aside as a savings transfer in your ledger and your safe-to-spend figure will exclude it automatically; whether it sits in a separate pot is a matter of taste.
Sinking funds versus an emergency fund
Sinking funds cover expenses you can predict; an emergency fund covers the ones you cannot. Mixing them means the car insurance quietly eats the cushion meant for a lost job. Keep the predictable bills in their own plan.
How Worth Clarity does it
Any yearly recurring expense rule doubles as a sinking fund. The sinking funds card on the budgets page spreads each into monthly set-asides at the steady pace and the catch-up pace, plus the combined monthly figure that covers everything. No new data entry: the bills you already track power it.
Common questions
- How is a sinking fund different from a savings goal?
- A goal is for something you want; a sinking fund is for something you owe on a known date. The mechanics are similar, but a sinking fund resets every cycle while a goal is finished when it is reached.
- What if the bill is bigger than expected?
- Cover the difference from safe to spend or the emergency fund, then raise the monthly set-aside for the next cycle so the fund matches the new reality.
- Should I keep sinking funds in cash or invest them?
- Cash or an instant-access savings account. Money you need on a fixed date within a year should not depend on the market that month.
