How to organize sinking funds

Option 1: one savings account, tracked in a sheet

All your sinking funds live in one savings account, and a spreadsheet says how much of that balance belongs to each fund. This is the easiest to set up and works at any bank. The risk is that the account looks like one big pile of money, so the tracker has to be kept current: every deposit and every withdrawal gets a line.

Option 2: separate accounts or buckets

Some banks and credit unions let you open several savings accounts, or sub-accounts sometimes called buckets or vaults, and name them. Each fund gets its own balance, so you can see at a glance what is available. It takes longer to set up and moving money between them is one more step, but there is less to track by hand.

Option 3: a mix

Many people keep the big funds (car, home repairs, vacation) in their own accounts and the small ones in one shared account with a tracker. Whichever you pick, keep sinking funds out of your everyday checking account. Money that sits next to your debit card tends to get spent.

Automate the deposits

Set one automatic transfer for the total sinking funds amount on payday. If you are paid biweekly, divide the monthly total by 26 and multiply by 12 to get the amount per paycheck.

Example with made-up numbers
Monthly total for all funds: 340
Per biweekly paycheck: 340 × 12 ÷ 26 = 156.92
Per weekly paycheck: 340 × 12 ÷ 52 = 78.46

The sinking fund calculator shows both amounts for each expense, so you can check the total before you set the transfer.

What to track for each fund

• Target amount and due date
• Current balance
• Monthly contribution needed to get there
• A short log of deposits and withdrawals with the date

Review it once a month, on the same day. It takes ten minutes: check that the balances in the sheet add up to what is really in the account, and adjust any contribution that is behind.

When the bill is higher than the fund

It will happen. The insurance renewal comes in 8% higher or the car repair costs more than you budgeted. Pay the difference from the current month's budget if you can, or borrow from a fund whose bill is far away and pay it back over the next months. Then raise the target for next year. Avoid taking it from the emergency fund unless it really is an emergency.

When a fund has money left over

If a bill comes in lower, you can roll the extra into next year's fund for the same expense, or move it to a goal that is behind. Do not let it drift into everyday spending: decide where it goes the day the bill is paid.

Resetting after the bill

Once a yearly bill is paid, the fund starts again from close to zero with a new target and due date. Write the new numbers the same week so the contribution continues without a gap.

If you are still choosing categories, the sinking funds categories list has 35 examples. For the overall budget around them, see the zero-based budget guide.

General information, not financial, tax or legal advice. Examples use made-up numbers.