Expenses only reduce your tax bill if you recorded them. Here is a system that takes two minutes a week, covers the ones with no paperwork, and keeps the file on your own machine.
Log it the day it happens, in one file, with the date, the amount, the category, and which job it belongs to.
That is the whole system. The reason people end up doing it badly is not complexity — it is that they leave it, and then face six months of receipts in a drawer on a Sunday afternoon in front of a deadline.
Two minutes a week beats four hours in March, and produces better numbers, because the entries were written while you still remembered what they were for.
Not the large ones. Nobody forgets a vehicle or a machine. What disappears is the constant trickle of small, legitimate costs that never generated paperwork you kept.
Parking. Tolls. Fuel paid in cash. Mileage in your own car. Coffee bought while waiting for a client. Lunch on a site visit two hours away. The taxi from the station.
Consumables bought in passing — a box of screws, a can of something, a cable, gloves. Individually trivial, collectively substantial over a year.
Software subscriptions that renew silently on a personal card. Domain renewals. The phone bill that is mostly business. A share of household costs where you work from home.
Small tools that fall below the threshold for capital treatment. Professional subscriptions and memberships. Bank charges. Currency conversion fees. Interest on business borrowing.
And postage, printing, and the two hundred small things that genuinely happened and left no trace.
None of this is exotic. All of it is deductible in most systems, and most of it evaporates because nobody wrote it down within a week of it happening.
This is the part that stops people, and it should not.
A missing receipt does not make an expense fictional. What tax authorities want is a reasonable, contemporaneous record — and in most systems a dated log entry, supported by a bank or card statement, is acceptable evidence for ordinary small amounts. Cash with no paperwork at all is weaker, which is why writing it down the same day matters so much: an entry made on the day is a record, and an entry reconstructed in March is a guess.
Photograph the paper ones straight away, because thermal receipts fade to blank within months and a faded receipt is no receipt.
For mileage, log the date, the journey and the distance. That is what the rules actually ask for in most places, and it is the single largest expense most small operators under-claim.
Two things to keep straight, though, because they are different questions and people run them together.
Sloppy record-keeping is not the same as anything improper, and the fix for it is a log. But a log is a record of what happened — it does not turn a personal cost into a business one. Where something is genuinely part personal and part business, record the split honestly and write down the reasoning. That is not caution; it is what makes the claim survive being questioned.
Money is the last thing most people talk about honestly, and it is not always the tax office they are keeping it from.
A spouse who worries. A colleague at the next desk who can see the screen. A business partner who does not need to know what you spend on what. A family member who asks. Somebody who takes an interest in what you earn and would take a keener interest in what you spend.
There is nothing improper in wanting your own financial records to be your own. It is the most ordinary thing there is.
Which is an argument for a file on your machine rather than an account with a cloud service. A spreadsheet is opened by you, backed up where you choose, and shared with your accountant when you decide to share it. There is no dashboard, no login somebody else might stay signed into, no app on a phone that somebody picks up.
A year of small costs, logged as they happen: parking, tolls, mileage, consumables, three subscriptions, a share of the phone bill. None over a modest amount. Together, a meaningful sum, and every entry supportable by a dated log and a statement line.
The same year, unlogged: about a third of it survives to the accountant, because that is the third with paper still in the drawer. The rest was real, was spent, and cannot be claimed for.
Nothing was done wrong in the second version. It just cost money to be disorganised.
How long should I keep records?
Typically between five and seven years depending on the country, and longer where property is involved. Check your own rules; digital copies are accepted nearly everywhere.
Do I need accounting software?
Not until volume or a legal filing requirement makes it necessary. A spreadsheet with the right columns handles a great many small businesses for years, and hands over to an accountant cleanly.
What categories should I use?
Match whatever your tax return asks for. Copying the boxes on the form means no re-sorting at the end of the year.
Should I track expenses per job as well as per category?
Yes, if you do project work. Categories tell you what you spent. Per-job tracking tells you which work was actually profitable, which is the more useful of the two.
The KISS Expense Tracker is a spreadsheet with categories, dates, per-job allocation and automatic monthly summaries. It sits on your own computer — no account, no cloud service, no subscription, nobody else's dashboard. Three euro, one file.
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