What to record on the job so the invoice writes itself

By the time you're home, the details blur. Three things recorded on the job — hours, rate and materials — turn invoicing into a formality instead of a memory test.

Hours live on a notepad, a phone note, or in your head. Receipts live in the van. By invoice time the hours are rounded down, the receipt is still in the glovebox, and the run to the merchants never lands on the client's invoice.

The fix isn't more discipline at the end of the week. It's capturing three things while the job is still in front of you.

1. The hours you actually worked

Note when you started and when you finished — including the awkward middle bits. The half hour diagnosing the fault, the second trip up the stairs, the wait for the part: that's the difference between billing the day you remember and the day you worked.

If you track time as you go, even roughly, you bill the real job. If you reconstruct it a week later, you bill a conservative guess — and the guess always rounds down.

2. The rate that applies to that client

If different clients are on different rates, the rate belongs with the client, not in your memory. Store it once when you set the client up, and every entry after that costs the right amount without you deciding anything.

This also removes the most common invoice dispute: "I thought we agreed £X". The rate is on the record before the work starts.

3. The materials, when you buy them

The screws, the sealant, the run to the merchants — small costs that add up to real money across a month, and that quietly never reach the bill. Record the material and its cost the day you buy it, against the job it was for.

Labour and materials belong on the same invoice, totalled together. The client sees the whole job; you recover the whole job.

What this looks like in practice

A boiler service at 14 Mill Lane: you track 4.25 hours against the job, log the copper elbows and the flue seal kit when you get them, and the client's rate is already saved from last time. When the job is done, the invoice is arithmetic — hours × rate, materials listed, total clear — and it can go out before you leave the drive.

That's the whole loop: track hours free, add the materials, send the invoice. Nothing re-typed, nothing remembered, nothing left in the van.

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