# What are sinking funds?

> A sinking fund is money you set aside a little each month for a bill you know is coming, like car insurance in June or gifts in December.

From Simple Balance: https://smpl.money/learn/sinking-funds/. Updated 2026-10-25.


A sinking fund is money you set aside each month for a bill you know is coming
but don't pay every month. Instead of finding $600 for car insurance in June,
you put away $100 a month starting in January.

## What it is

The name comes from business. When a company borrows money by selling bonds, a
sinking fund is how it pays them back a little at a time instead of all at
once. [FINRA explains bonds](https://www.finra.org/investors/investing/investment-products/bonds)
if you're curious. In a household budget, a sinking fund is the same idea:
**a known amount, needed by a known date, saved in equal pieces**.

**Diagram: Put away $100 a month from January, and the fund reaches $600 in June, the month the bill is due. Then the fund pays the bill.** A bar for each month from January to June, each one a stack of $100 pieces: $100 in January, $200 in February, $300 in March, $400 in April, $500 in May and $600 in June. A dashed line marks the $600 car insurance bill, and the June bar reaches it exactly. An arrow from the June bar pays the bill, drawn as a $600 bar of its own.

It's different from an [emergency fund](https://smpl.money/learn/emergency-fund/). An emergency
fund covers things you can't predict, like losing a job or getting in a car
accident. A sinking fund covers things you can. The holidays come every
December.

Common sinking funds include:

- Car insurance, registration and upkeep
- Holiday and birthday gifts
- A vacation
- Yearly subscriptions and memberships
- Back-to-school costs
- Medical bills up to your insurance deductible
- A new phone or laptop
- Vet bills

## Why it matters

Bills that don't come every month are easy to forget. A monthly budget can look
fine for eleven months, and then the car insurance bill shows up. Without a
sinking fund, that bill often goes on a credit card, and you start the next
month behind.

Small amounts are easier to handle than big ones. Setting aside $75 a month is
one more line in your budget. Finding $900 in December is a scramble.

And when the bill comes, you're ready. Paying it from money you saved for it
means your plan worked.

## How to do it

### 1. List the bills for the next twelve months

Look through last year's statements for anything you paid once or twice:
insurance, renewals, gifts, trips. The list may be longer than you expect.

### 2. Work out the monthly amount

Divide each bill by the number of months until it's due. For bills that come
once a year, [Utah State University Extension](https://extension.usu.edu/finance/faq/budget-for-non-monthly-expenses)
and Oregon's
[Division of Financial Regulation](https://dfr.oregon.gov/financial/manage/pages/budget.aspx)
suggest the same thing: divide by 12 and set that much aside every month.

| Bill          | Amount | Due in    | Each month |
| ------------- | ------ | --------- | ---------- |
| Car insurance | $600   | 6 months  | $100       |
| Holidays      | $900   | 10 months | $90        |
| Vet checkup   | $240   | 12 months | $20        |

**Diagram: Each bill is cut into one equal piece for every month until it’s due. The holidays cost the most, but with 10 months to save, each piece is smaller than car insurance’s.** Three bars on the same scale, each cut into equal monthly pieces. Car insurance, $600 due in 6 months: 6 pieces of $100. Holidays, $900 due in 10 months: 10 pieces of $90. Vet checkup, $240 due in 12 months: 12 pieces of $20.

The later you start a fund, the more you have to save each month. That's a
good reason to start all of them now.

### 3. Set the money aside

You can move it into a separate savings account. Or you can leave it in
checking and keep a list of how much belongs to each fund. Either way works,
as long as you don't count that money as free to spend.

### 4. Pay the bill from the fund

When the bill comes, the money is waiting. Pay it, then start saving again for
next time.

## How to do it in Simple Balance

A budget in Simple Balance can save toward a date on its own.

### Set the goal

On [**Budgets**](https://smpl.money/docs/budgets/), under **Set a budget**, choose the category
you'll pay the bill from, like Car insurance. Type the bill's amount in **Saving
up for**. A **Needed by** box then appears: type the due date there, not in
**Ends after**.

![The budgets screen: a form for setting one, with fields for the category, the amount and how it's decided, the currency, a start date and an optional end date, an optional savings goal and which budget gets funded first, and a checkbox for carrying what's left into next month. Below it, the list of standing budgets begins with $200 a month for dining out.](https://smpl.money/screenshots/budgets-light.webp)

_The money in this picture is made up. It's the real product, filled with
example spending._

### Let it work out the amount

You don't type a monthly amount. Each month, the budget figures out what's still
needed and divides it by the months left before the due date. The amount changes
as the fund fills up, and it stops asking once the fund is full. **Carry what is
left over into the next month** is turned on for you, since a fund has to keep
what it saves.
[Saving goals, automatic amounts and the forecast](https://smpl.money/docs/planning-ahead/#how-much-each-month-asks-for)
in the docs shows exactly how each month's amount is worked out.

### Pay the bill from the same category

When the insurance bill comes, record it in the Car insurance category. The
money the budget set aside covers it.

### Know where the money is

A fund is money in your accounts that's set aside for one job. The **Budgets**
page shows what's **left to assign** after every fund and envelope has taken
its share, which tells you how much is really free to spend. If you keep the
fund in a separate savings account, leave **The budget is about the money in
this account** turned on for that account, so its money still counts.

![A list of transactions, newest first, each with who it was with, which account it was in, its category and its amount, all in dollars. Most are spending on groceries, a lunch, cinema tickets and a transit pass. One is a $750 freelance payment coming in, and one is $600 moved from checking to savings, which shows both accounts and no category.](https://smpl.money/screenshots/transactions-light.webp)

_The money in this picture is made up. It's the real product, filled with
example spending._

### One fund for each bill

Each fund belongs to the category it's saving for. Holiday gifts, insurance and
a vacation each get their own budget, and each works out its own monthly
amount.

## Sources

- FINRA. [Bonds](https://www.finra.org/investors/investing/investment-products/bonds).
- Melanie Dabb, Utah State University Extension. [How do I budget for non-monthly expenses?](https://extension.usu.edu/finance/faq/budget-for-non-monthly-expenses). October 13, 2020.
- Oregon Division of Financial Regulation. [Creating a personal budget](https://dfr.oregon.gov/financial/manage/pages/budget.aspx).

