Side hustle tax app

The side hustle tax app for the UK

Hamster is a side hustle tax app for the UK that shows the tax and National Insurance you’re building up as you earn, and how much to set aside for it. Log a sale, a shift or a cost and the estimate updates straight away, so January’s bill is one you’ve already saved for.

Android app on Google Play

Download free

Built for UK sole traders and side hustlers (HMRC rules)

Hamster’s dashboard showing £2,000 of income logged this tax year, £400 of estimated tax and National Insurance owed, the amount set aside so far, and the days left until the Self Assessment deadline.

Who it’s for

Anyone in the UK earning on the side as a sole trader: selling online, driving or delivering, freelancing, tutoring or creating content, usually alongside a job. Nothing is taken off what you earn on the side, so the tax builds up quietly until your Self Assessment bill arrives.

It isn’t built for limited companies or partnerships. Estimates use the rates for England, Wales and Northern Ireland. Scottish Income Tax bands and student loan repayments aren’t included yet.

What Hamster does

You log what you earn and spend, and your business miles. Hamster estimates your Income Tax and Class 4 National Insurance for the tax year, taking your salary into account, and tells you what to set aside. It doesn’t connect to your bank, track you by GPS or file your tax return. You stay in control of what goes in.

The features that matter

Free
Log earnings, costs and mileage
Add each sale, shift or cost in a few taps, and log business trips by the mile. Everything is kept by tax year.
Free
Tax worked out on top of your salary
See your Income Tax and National Insurance estimate update as you log. Hamster uses the £1,000 trading allowance until your costs beat it.
Free
Know what to set aside
See what you should have put away by now, record what you have, and get a weekly nudge to keep up.
Premium
Import from Uber or Deliveroo
Bring in an Uber or Deliveroo CSV export instead of typing every trip, and get an alert when you cross a key tax threshold.

Pricing

Hamster (free): Log earnings, costs and mileage, see your tax and National Insurance estimate, and track what you’ve set aside. Free to download and free to use.
Hamster Premium: £4.99 a month or £47.99 a year, billed through Google Play. Adds CSV import, receipt photos, the accountant PDF and threshold alerts. Cancel any time in Google Play. Free trial available on Google Play for eligible accounts.

Questions

Is Hamster free?

Yes. The core app is free: logging, the tax and National Insurance estimate and set-aside tracking. Hamster Premium is optional, at £4.99 a month or £47.99 a year through Google Play. A free trial is available on Google Play for eligible accounts.

Does it connect to my bank or track my location?

No. Hamster never asks for bank access and doesn’t track you by GPS. You add your earnings, costs and business miles yourself, or with Premium you can import an Uber or Deliveroo CSV export.

How does it work out what to set aside?

It estimates the Income Tax and Class 4 National Insurance on your side hustle profit for the tax year, with your profit stacked on top of any salary. That estimate is what you should have set aside so far, and you record what you’ve actually put away next to it.

Is there an iPhone version?

Not yet. Hamster is Android only for now, on Google Play.

Want the rule of thumb first? Read how much to set aside for tax on a side hustle, or try the free side hustle tax calculator. Filing your first return? See Hamster as a Self Assessment app for side hustlers.

Get Hamster

Android app, out now on Google Play. Estimates are a guide, not tax advice. How we check our numbers.