The expenses that quietly become your problem
Nobody forgets to bill a €900 flight. What goes unbilled is everything in the middle: the stock photo license, the extra seat on a tool you bought for one project, the taxi, the courier, the domain you registered because it was faster than asking, the day you drove somewhere and back.
Individually each is too small to chase, which is exactly the mechanism. Across a year they add up to a number most people would be annoyed by if they ever saw it in one place, and they land entirely on your side of the margin, where they make an otherwise fine project look worse than the work deserved.
The other category is time, which people forget is an expense at all. Travel time, waiting time, the half day lost to a site visit. Those hours cost you whatever you would have billed them at, which is one more reason to know that number. If it is not in the agreement, you paid for it.
Agree it before you spend it
This is the whole game, and it takes two sentences in the proposal.
Say what is included in your rate and what is billed separately. Give a threshold above which you ask first, low enough to be meaningful and high enough not to be annoying: a hundred euros works for most kinds of work. Say how travel time is treated, because that is the one people disagree about after the fact.
The reason this works is not legal, it is psychological. An expense that was agreed in advance arrives on the invoice as an expected line. The identical expense that was not agreed arrives as a surprise, and surprises on invoices are what make clients read the whole thing suspiciously.
- What the rate already covers: your own tools, your own software, your own equipment.
- What is billed on: travel, accommodation, third-party licenses bought for this project, subcontracted work.
- The threshold above which you ask first, in writing.
- How travel time is treated: billed, half-billed, or not billed.
- Whether you add a handling percentage, and how much.
Keeping the evidence while it still exists
A receipt is a piece of evidence with a short life. Paper ones fade and get lost, and email ones become unfindable within about three weeks of arriving.
The habit that works is capture at the moment, filed against the project, not sorted at the end of the month. Sorting at the end of the month sounds efficient and is the reason half of them are missing: by then you cannot remember which client the parking was for.
What matters when it comes back up is being able to answer three questions: what was it, which project was it for, and can you produce the document. In Steerd a receipt attaches to the project itself, encrypted, and filed under an expense category, so it sits with the job rather than in a photos app. Anything that does not belong to one project goes in the team document vault instead, which searches by filename and previews in the browser. What there is not is receipt scanning: nothing reads the amount off the picture for you, and nothing here should be read as saying it does.
Getting it onto the invoice
The failure here is timing, not honesty. Expenses go unbilled because the invoice is written on the first of the month from the hours, and the expenses live somewhere the invoice never looks.
Two habits fix nearly all of it. Add the expense to the project the day it happens, not the day you invoice. And check the project for open expenses before you send an invoice, especially the final one, because after the final invoice the conversation gets meaningfully harder.
List expenses as their own lines with dates and descriptions rather than folding them into a total. A client who can see what each one was almost never queries it. A single line reading "expenses, €740" gets queried nearly every time.
Markup, handling fees, and being straight about them
Adding a percentage to expenses is normal and defensible. You carried the cost, you took the risk, and you spent time arranging it. Ten to fifteen percent is common on subcontracted work and materials.
The rule is that it has to be visible. A handling fee stated in the proposal and shown on the invoice is a business term. The same amount hidden inside a marked-up line is something a client will eventually notice, and what they will remember is not the money.
For pure pass-throughs, a train ticket bought on their behalf, most people add nothing, and it buys a surprising amount of goodwill for what is usually a small sum.
What to leave to your accountant
This page is about getting paid back, not about tax. Whether an expense counts as something you paid on the client's behalf or as your own cost passed on, and what happens to the tax on it, differs from country to country and sometimes from case to case.
That distinction changes what goes on the invoice and how it is treated afterwards, so it is worth asking your accountant once, in the specific terms of your own business, and then applying the answer as a habit. It is a five-minute question you only have to ask once, and getting it wrong is tedious to unwind.
What is worth doing regardless of the answer is keeping the evidence attached to the project, because every version of the answer requires exactly that.