What Is a Sinking Fund? How Families Save for Bills They Know Are Coming

Short answer: What is a sinking fund? It's money you set aside a little at a time for a specific expense you know is coming, like holiday gifts, back-to-school costs or a car insurance bill. You divide the total by the weeks or months until it's due and save that amount on a schedule. When the bill arrives, the cash is already there, so you don't need a credit card or your emergency fund.

"Sinking fund" is an informal budgeting term, not a special kind of account. The idea behind it shows up throughout government saving guides. The Consumer Financial Protection Bureau (CFPB) lists "annual expenses like children's school supplies" among the things people save for, and the FDIC tells families to look at expenses they pay annually or semiannually, such as taxes or insurance premiums, and build them into their plan.

How Does a Sinking Fund Work?

A sinking fund turns one big bill into many small ones. The CFPB's savings booklet describes the habit this way: automatically depositing a monthly amount into a savings account, so when a lump-sum payment is due the money is already saved. It says this helps reduce stress when large, periodic payments, like car insurance or school tuition, come due.

The basic steps:

1. Pick the expense. Choose one bill you know is coming.
2. Find the total and the date. How much will it cost, and when is it due?
3. Do the math. Divide the total by the number of weeks or months you have.
4. Save on a schedule. Move that amount into savings every week, month or paycheck.
5. Spend it on that bill. When the expense arrives, pay it from the fund and start the next cycle.

How Much Should You Save Each Month?

The CFPB's savings plan tool spells out the formula: divide the amount you want to save by the number of weeks you have to save it, and that's your weekly savings target. Its example is saving $1,000 in about 40 weeks, or $25 a week. The CFPB's savings booklet uses $400 over 20 weeks, or $20 a week. The tool says breaking a goal up this way makes saving easier by turning it into manageable pieces.

Here's how that math could look for a family. The amounts below are made up to show the method, not typical costs:

Expense	Total needed	Time until due	Amount to set aside
Holiday gifts	$600	12 months	$50 a month
Car insurance (twice a year)	$720	6 months	$120 a month
Back-to-school clothes and supplies	$300	10 months	$30 a month
Car maintenance and tires	$480	12 months	$40 a month
Total			$240 a month

The CFPB suggests picking a saving frequency that fits your needs, such as once a week, once a month or once per paycheck. If you're paid every other week, dividing by the number of paychecks before the due date works the same way.

Sinking Fund vs. Emergency Fund: What's the Difference?

Both are savings, but they cover different kinds of costs:

	Sinking fund	Emergency fund
What it's for	A specific expense you know is coming	Unplanned expenses or financial emergencies (CFPB)
Examples	Holidays, school supplies, insurance premiums	Car repairs, home repairs, medical bills, a loss of income (CFPB)
How much	The bill's cost, divided over the time until it's due	A goal based on the unexpected expenses you've had before (CFPB)
When you spend it	On a date you can plan for	Whenever an emergency happens

Keeping the two apart protects your emergency savings. The CFPB's savings booklet says to try to use the money in a rainy day fund only for unexpected expenses. If the holiday bills or the car insurance premium come out of that fund instead, it may not be there when a real surprise arrives. Our guide to building an emergency fund covers how much to keep for surprises.

What Are Common Sinking Fund Categories for Families?

Look back at the past year for costs that came once or twice. The CFPB and FDIC name several:

• Annual expenses like children's school supplies (CFPB)
• Large periodic payments like car insurance or school tuition (CFPB)
• Expenses paid annually or semiannually, such as taxes or insurance premiums (FDIC)
• Anticipated costs, such as education (FDIC)
• Personal goals, like a new TV, appliances or a car (CFPB)

You might also plan for holidays and birthdays, summer camp, annual memberships, vehicle registration or travel. For long-range goals like college, a dedicated account may fit better; our guide to the 529 plan vs. a custodial account compares two options.

Where Should You Keep a Sinking Fund?

Pick a place that's safe, easy to reach when the bill is due, and separate from your everyday spending money. The CFPB's savings booklet lists bank and credit union accounts as places to keep savings and notes both are federally insured. At an FDIC-insured bank, deposits are insured up to $250,000 per depositor, per insured bank, for each account ownership category.

Some ways to set it up:

• One savings account for everything. Keep a simple list or spreadsheet that tracks how much of the balance belongs to each category.
• A separate savings account for each goal. Ask your bank or credit union whether you can open more than one savings account.
• A higher-yield option for bigger, later bills. Our guide to money market vs. savings accounts explains the trade-offs.

If you're choosing where to bank, see our comparison of checking vs. savings accounts and our guide to FDIC insurance limits.

How Do You Stick With It?

Make the saving automatic. The CFPB says saving automatically is one of the easiest ways to save, and suggests setting up recurring transfers through your bank or credit union to move money from checking to savings. It also suggests watching your balances so a transfer doesn't cause an overdraft fee. The CFPB notes you may have an option to split your paycheck between checking and savings.

A few more habits from the CFPB and FDIC:

• Pay yourself first. The FDIC suggests treating your savings like a bill and paying yourself first, even if the amount seems small.
• Use one-time money. The CFPB points out that a tax refund can be one of the largest checks many people get all year, and cash gifts at holidays or birthdays can go toward savings too.
• Track your progress. The CFPB's savings booklet includes a tracker for following your savings from week to week.

What If a Bill Is Bigger Than You Planned?

If a bill comes in higher than you saved for, cover the gap from your regular budget if you can, then raise the monthly amount for next time. If you have to borrow, compare costs carefully; our guide to the debt snowball vs. avalanche can help you plan the payoff.

The Bottom Line

A sinking fund is a simple plan for expenses that aren't really surprises. List the bills you know are coming, divide each one by the time you have, and save that amount automatically in an insured account. The CFPB's tools use the same divide-and-save math. Keep it separate from your emergency fund so each one can do its own job. Browse our banking guides for more on where to keep your savings.

Frequently asked questions

What is a sinking fund in simple terms?

It's a savings pot for one known expense. Instead of paying a big bill all at once, you put a set amount aside each week or month so the money is ready when the bill arrives. "Sinking fund" is an informal budgeting term, not a type of bank account.

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

An emergency fund covers surprises. The CFPB describes it as a cash reserve set aside for unplanned expenses or financial emergencies, such as car repairs, medical bills or a loss of income. A sinking fund covers costs you know are coming, like annual school supplies or a car insurance premium, so they don't have to come out of your emergency savings.

How much should I put in a sinking fund?

Divide the total you'll need by the number of weeks or months until you need it. The CFPB's savings plan tool gives the example of saving $1,000 in about 40 weeks, which works out to $25 a week. Its savings booklet uses $400 over 20 weeks, or $20 a week.

Where should I keep a sinking fund?

Somewhere safe that you won't dip into for everyday spending. The CFPB's savings booklet lists bank and credit union accounts as federally insured options. FDIC deposit insurance covers up to $250,000 per depositor, per insured bank, for each account ownership category.

What are common sinking fund categories?

Any expense you can predict. The CFPB names annual expenses like children's school supplies and large periodic payments like car insurance or school tuition, and the FDIC mentions bills you pay once or twice a year, such as taxes or insurance premiums. You might also plan for holidays, birthdays and car maintenance.

Sources

1. CFPB: Your Money, Your Goals — Savings Booklet
2. CFPB: Your Money, Your Goals — Savings Plan Tool
3. CFPB: An Essential Guide to Building an Emergency Fund
4. FDIC Consumer News: Make a Financial Plan to See You Through (February 2021)
5. FDIC: Understanding Deposit Insurance

This guide is general information, not personal advice. Your situation may differ, so consider talking with a qualified professional, such as a fiduciary financial adviser, CPA or licensed agent, before making a decision.