How to track expenses you bill back to clients

Reimbursable expenses are money you have already spent on a client's behalf. Failing to recover them is not a missed opportunity, it is a direct loss, and it happens constantly because the expense and the invoice live in different places and different weeks.

Agree the rules before you spend anything

The awkwardness around rebilling comes entirely from ambiguity. Remove it in the contract:

• What is reimbursable. Travel, stock assets, third party licences, printing, subcontractors, hosting bought in their name.
• What is not. Your own tools, your own software subscriptions, your internet, your general overheads. These are covered by your rate.
• Whether a markup applies. Ten to twenty percent on pass through costs is common and defensible as handling and cash flow cost. If you apply one, say so up front.
• The approval threshold. Anything above a stated amount needs written approval first. This protects both sides.
• Documentation. Receipts provided with the invoice.

One short paragraph covering these prevents every rebilling dispute worth having.

Flag at the moment of purchase

The reason reimbursable expenses go unrecovered is that nothing marks them as different at the time. Three weeks later, the receipt is one of forty and looks like every other expense.

The habit that fixes it:

• Photograph the receipt immediately.
• Tag it to the client or project immediately.
• Mark it reimbursable immediately.

All three in the same ten seconds, at the counter. Anything that depends on a later filing session will fail during a busy month.

Pull them onto the invoice as separate lines

Reimbursable costs should never be folded into your fee. Show them as their own lines, clearly labelled, with the date and vendor:

• Flights, London to Berlin, 12 September, 284.00
• Stock photography licence, 8 September, 79.00

Two reasons. Finance teams approve documented pass through costs more easily than an unexplained increase in a fee, and separating them keeps your revenue reporting honest, since pass through money is not income in any useful sense.

Attach the evidence

Send the receipts with the invoice, not on request. It removes a round trip, it looks organised, and for clients whose expense policy requires documentation it is the difference between paying this week and paying next month.

Close the loop so nothing is billed twice

The failure mode after recovery is billing the same expense twice, which is worse than never billing it. The record needs to know that a given receipt has been invoiced, and on which invoice. When an invoice is cancelled, those expenses should become billable again rather than being stranded.

This is exactly the round trip the Durvy suite handles: Receiptly marks a receipt reimbursable and tagged to a project, Invoicy offers those receipts as one click lines on the invoice, the link is recorded both ways, and cancelling the invoice releases the receipt back into the pool.

The monthly sweep

Once a month, list every reimbursable expense that is not yet linked to an invoice. Anything older than a month goes on the next invoice or gets a deliberate decision to absorb it. That single query is usually worth more than any other five minutes in your admin block.

TL;DR

• Define reimbursable, non reimbursable, markup, approval threshold, and documentation in the contract.
• Photograph, tag to the project, and flag as reimbursable in the same ten seconds, at the point of purchase.
• Invoice them as separate labelled lines with receipts attached, never folded into your fee.
• Track which receipt landed on which invoice, and sweep monthly for anything unbilled.