I tracked every expense for a year as a UK freelancer. Here's what surprised me.

TL;DR: I was leaving about £2,400/year on the table by not claiming things I was entitled to. You probably are too. The stuff everyone claims Software subscriptions (GitHub, Figma, hosting) Hardware (laptop, monitor, keyboard) Phone bill (business portion) Yeah, you know these. Moving on. The stuff people forget This is where it gets interesting. Working from home allowance HMRC's simplified expenses: 25-50 hours/month working from home → £10/month 51-100 hours → £18/month 101+ hours → £26/month £26/month sounds pathetic. It is. But it's £312/year you're probably not claiming. Or calculate actual costs (proportion of rent/mortgage interest, electricity, heating, council tax, internet). Usually works out higher. I claimed £1,200 last year on actuals. Mileage 45p per mile for the first 10,000 miles. 25p after that. I drive to maybe 15 client meetings a year. Average 40 miles round trip. That's 600 miles × 45p = £270. Not life-changing, but it's there. Free mileage calculator → Profession