An irregular expenses budget covers the bills that do not arrive every month: car registration, insurance paid yearly, holiday gifts, school fees and repairs. Find them by searching 12 months of bank statements for payments that appear once, twice or four times a year. Add up the year's total, divide by 12, and set that amount aside every month.
What counts as an irregular expense in a budget?
An irregular expense is any cost you can expect but that does not land every month. Some are fixed and dated, like an annual insurance premium. Some are certain but uneven, like gifts. Some are likely but unscheduled, like car repairs. All three belong in the plan, because each one will hit a month that was budgeted as normal.
It helps to sort them into three groups, because each group is estimated differently:
- Fixed and dated. The amount and the month are both known, give or take a little. Examples: an annual car registration, a yearly software or warehouse club membership, property tax paid in two instalments, a renters insurance premium paid once a year.
- Seasonal. The month is known but the amount moves. Examples: holiday gifts in December, back-to-school costs in August, a summer trip, heating oil deliveries in winter.
- Unscheduled but expected. Neither date nor amount is known, but something will come up. Examples: car repairs, vet bills, replacing a phone or a laptop, a dental crown.
What does not belong is a true emergency, such as a job loss. That is what an emergency fund is for. The irregular expenses list is for costs that are surprising only in timing.
Searching 12 months of statements for irregular bills
The fastest way to find irregular bills is to put 12 months of statement rows in one sheet and look for payees that appear between one and four times. Monthly bills show up 12 times, and daily spending shows up dozens of times. Anything in between is a candidate for the irregular list.
A full year matters. Three months of statements will miss the car registration due in October and the gifts bought in December. Twelve months catches each yearly cycle once.
Here is a step list for the search, in Excel or Google Sheets:
- Combine the year's rows on one tab. Paste each month's statement below the last, with the same columns: date, description, amount.
- Add a cleaned Payee column. Strip store numbers and dates so "GEICO *AUTO 0412" and "GEICO *AUTO 1011" read as one payee. A short lookup list of payee fragments does this.
- Count rows per payee. In Excel or Google Sheets,
=COUNTIF(D:D, D2)in a new column gives the number of times each payee appears. A pivot table with Payee on Rows and Count of Amount in Values does the same. - Filter to payees with a count of 1 to 4. These are your candidates.
- Sort the candidates by amount, largest first. The big ones matter most.
- Scan the remaining rows for one-off large amounts. Some irregular costs come from payees you use for everyday spending too, like a $640 tyre purchase at the same store where you buy fuel. Sort the whole year by amount and look at the top 30 rows.
Expect to find costs you had forgotten. A yearly renewal you set up three years ago is the classic case.
Business owners will find extra items here: quarterly estimated taxes, annual licences, a yearly accountant fee. Those belong in the business books, not the household budget. If you are untangling a mix, a simple chart of accounts for a small business shows where those business rows should go.
Turning irregular expenses into one monthly budget amount
To turn irregular expenses into a monthly amount, add up the yearly total of every item on your list and divide by 12. For fixed items, use last year's amount, plus any known price increase. For seasonal and unscheduled items, use last year's figure as a floor and round up. The result is the amount you move aside each month.
A few rules make the arithmetic hold up:
- Use what you actually paid. Last year's statement rows are better evidence than a guess at what something "usually" costs.
- Round up, not down. A plan that is $10 too generous each month leaves $120 spare at year end. A plan that is $10 short leaves a gap in the month the bill arrives.
- Treat repairs as an average. If you spent $1,100 on car repairs last year and $400 the year before, use a figure near the two-year average or a little above it, not the low year.
- Count the item, not the payment. Property tax paid in two instalments is one yearly figure, split however you like.
The monthly set-aside goes in the budget like any other line. On months when no irregular bill arrives, the money accumulates. When the bill comes, the money is already there, and the month's normal budget stays intact.
Some people prefer a separate line for each irregular item, each with its own running balance. That approach, known as sinking funds, gives more visibility at the cost of more lines. The guide to building a sinking funds spreadsheet shows how to track several balances side by side.
Worked example: an irregular expenses budget from one example year
The example below lists the irregular bills found in 12 months of made-up statements for one household and turns each into a monthly set-aside. All payees and figures are examples. Last year the items came to $5,333, and the plan for next year is $5,685, or $473.75 a month.
| Item | Type | Month(s) seen | Last year's total | Planned for next year | Monthly set-aside |
|---|---|---|---|---|---|
| Car insurance, 6-month premium | Fixed | Mar, Sep | $1,128 | $1,200 | $100.00 |
| Car registration | Fixed | Oct | $186 | $190 | $15.83 |
| Renters insurance, annual | Fixed | Jan | $164 | $170 | $14.17 |
| Warehouse club membership | Fixed | Jun | $65 | $65 | $5.42 |
| Cloud storage, annual plan | Fixed | Feb | $100 | $100 | $8.33 |
| Holiday gifts | Seasonal | Nov, Dec | $780 | $800 | $66.67 |
| Birthdays | Seasonal | Spread | $340 | $360 | $30.00 |
| Back-to-school | Seasonal | Aug | $420 | $450 | $37.50 |
| Summer trip | Seasonal | Jul | $1,050 | $1,100 | $91.67 |
| Car repairs | Unscheduled | Apr, Nov | $890 | $1,000 | $83.33 |
| Vet visits | Unscheduled | May | $210 | $250 | $20.83 |
| Total | $5,333 | $5,685 | $473.75 |
Rounded, the household sets aside $475 a month.
Notice how uneven the year is. In September, the six-month insurance premium arrives on its own. In November, gifts and a car repair land together. Without the set-aside, November would look like a month of overspending, even though every cost was predictable from the previous year.
The plan for next year is higher than last year's actual total in most rows. Insurance and repairs in particular tend to creep up, and a small cushion costs little.
Where should the irregular expenses money sit until the bill arrives?
Irregular expenses money is easiest to manage in a separate savings account that you do not use for everyday spending. Set up an automatic transfer on payday for the monthly amount. When a bill arrives, move the exact amount back to checking and pay it from there, so the bill shows on your normal statement.
A separate account helps in three ways:
- It stops the money from looking spendable. A checking balance that includes $2,000 of saved-up insurance money invites spending it.
- It gives you a running total you can check. The savings balance should roughly equal the months saved times the monthly amount, minus bills already paid.
- It keeps the history readable. Transfers in and out appear on both statements, which makes the year easy to review.
Those transfers need care in the budget itself. A transfer to savings is not spending, and counting it as spending, and then counting the bill again when it is paid, doubles the cost. Tag both legs of each transfer so they stay out of your spending totals.
Variable earners have a harder version of this problem, because the monthly set-aside has to come out of uneven pay. The approach to budgeting on variable income from past deposits plans around the low month, and the irregular set-aside is one of the lines it protects.
Irregular expense edge case: bills that change size or skip a year
Some irregular expenses do not repeat neatly. A bill may grow sharply, change frequency, or appear only every two or three years. Handle these by planning on the expected cost per year, not on what happened in the last 12 months. A two-yearly bill of $300 needs $150 a year, or $12.50 a month.
Common examples and how to treat them:
- Bills that come every two or more years. Passport renewals, a driver's licence, new tyres, a laptop replacement. Twelve months of statements may not show them at all. Add them from memory or older statements, and divide the cost by the number of years between them.
- Bills that jump. An insurance premium that rises after a claim, or a property tax reassessment. Use the new figure as soon as you know it, and top up the savings account for any shortfall.
- Bills that change schedule. A premium that moves from yearly to monthly stops being irregular. Move it to the regular budget and remove it from this list.
- One-off costs that will not repeat. A wedding you attended, a one-time move. Leave them out of next year's plan, but note them so the history makes sense.
Review the list once a year, ideally just after you have a fresh 12 months of statements. Strike items that ended, add any new ones, and update the amounts from what you actually paid.
The yearly review is far easier with statement rows already in a spreadsheet. CheapBankConvert turns a PDF statement into CSV or Excel rows, and a bundle of five statements is priced at $9.99 in its early pricing, so a year of statements does not need a subscription. It has not opened yet; get started to hear when it does.