Irregular expense

A monthly budget assumes each month pays for itself, and an irregular expense breaks that assumption in both directions: the month it lands in looks like a disaster, and the months before it looked better than they were. The premium paid every six months, the registration, the annual renewal and the car that needs tires are not surprises. An irregular expense is a known cost with an unusual schedule, and it is turned into a monthly amount by dividing it by the months between occurrences, or, when it has no schedule, by dividing what it cost over two years by 24. Budgeted that way, the month it lands in never absorbs it alone.

In a sentence

• "The $840 insurance premium is the irregular expense that wrecked March every year, so it is $140 a month now, all year."
• "An irregular expense is not an emergency. The premium was known in January; the transmission was not."
• "Between the premiums, the registration, the renewals and the water bill, our irregular expenses come to $350 a month that no single statement ever shows."

How it works

Irregular expenses come in two kinds, and the kind decides how the monthly share is found.

1. List every expense that is not monthly. Read twelve months of statements from every account, cards included; a card hides annual charges inside one monthly payment.
2. Divide each periodic bill by its interval. An $840 premium every six months is $140 a month.
3. Size each no-schedule expense from its history. Two years of car repairs divided by 24, seeded with one repair's worth so the first year is not short.
4. Add up the shares. That total leaves the spendable budget every month, or one of these bills lands unfunded.
5. Give the money somewhere to sit, a savings account or a budget category that carries its balance forward, and pay each expense from the balance when it lands.
6. Check once a month how far behind you are. The next payment minus what is set aside, divided by the months left, is the catch-up share; when it exceeds the regular share, you are behind and you know it months early.

Monthly share = amount ÷ months between payments

An example

This household has $350 a month of expenses that appear in a handful of months, $4,200 a year, and a budget without lines for them is right for most months and wrong for the ones that matter. Started mid-cycle, the share needs a catch-up: with the premium due in two months and $280 set aside, the gap is $560, so the next two months need $280 each, twice the regular share, and $140 resumes once the premium is paid.

Why it matters

Irregular expenses are the usual reason a budget that works in most months fails in one, and the failure has a pattern: the premium lands, it goes on a card or comes out of the emergency fund, and the household feels behind for two months. Turning each one into a monthly share makes the real cost of the household's commitments visible before any month starts, keeps the card and the emergency fund from becoming the fallback, and turns a repair that arrives on a Tuesday into a withdrawal.

The mistake it prevents is counting the set-aside as savings. The $350 is a bill in slow motion, not a cushion, and a household that spends it because the balance looked spare is exactly $350 short in the month the premium lands.

Irregular expense versus an emergency

An irregular expense is known in amount or in rate; an emergency is necessary, unexpected and urgent, all three. The premium and the registration are known to the dollar and the date, and a car's repairs are known in aggregate even though no single one is, so all of them are budgeted from a monthly share. The job loss, and the transmission that costs more than the repair balance holds, belong to the emergency fund. Paying a known bill from the emergency fund mislabels it as a surprise, and the fund is that much smaller on the day a real one arrives.

Common questions

Is an irregular expense the same as a variable expense? No. A variable expense changes in amount from month to month with your decisions; an irregular expense does not arrive every month. A premium is fixed in amount and irregular in timing, and groceries are variable in amount and monthly.

Is budgeting for irregular expenses the same as a sinking fund? Yes. A sinking fund is where the monthly shares collect, and dividing the expense by the months until it is due is how the fund is sized. One savings account can hold several, with a list of what each balance covers.

What if I cannot afford the full monthly share? Set aside what you can and write down the shortfall. A bill you know will be $200 short in four months can still be solved, by trimming elsewhere or by choosing monthly billing for that one bill; a bill you forgot is solved with a credit card.

Should I switch irregular bills to monthly payments instead? Sometimes. Monthly billing often costs a few percent more and removes the planning problem entirely; paying annually and setting aside the share yourself is cheaper, but only if you actually do it.

Go deeper

• How to budget for bills that aren't monthly turns each non-monthly bill into a monthly share and shows how far behind you are.
• How to build a sinking fund, and how many to keep sizes each fund, catches up a late start and keeps several in one account with a list.
• How to budget for car repairs and other expenses with no schedule sizes a share from two years of history and seeds it so the first repair is covered.

Where it shows up in Zypper

Zypper budgets an irregular expense on its real cadence. Give a category a Spending frequency of Every three months, Every six months or Every year, with the full amount for each occurrence, and the Monthly equivalent is shown. A cadence longer than a month turns on Roll over unspent budget for the category, so each month's share accumulates and the carried balance shows beside the amount. Once the bill has been identified from your transactions, Zypper holds back a reserve from the carried balance for the next due date, and the pill reads $X short when the balance you have built will not cover it. See Creating your budget and Recurring bills in your budget for the details, or get started with Zypper to see your own bills this way.