Know what to set aside for tax, before HMRC tells you.
Log your side-hustle earnings and costs. Hamster estimates the tax and National Insurance you’ll owe on top of your job, shows what to put away, and gets your figures ready for Self Assessment.
Free on Android
Free core app. Premium £4.99 a month, yearly option available. 14-day free trial on Android.
- No bank login
- Your figures stay on your phone
- Built for UK tax rules
How it works
Three steps, all year round
1Log what you earn and spend
Add a sale, a shift or a cost in a few taps, plus your business miles. No bank login, no spreadsheet.
2See what to set aside
Hamster estimates your Income Tax and Class 4 National Insurance on top of your salary, and shows what you should have put away by now.
3Get ready for Self Assessment
Everything is kept by tax year. With Premium, export a PDF labelled by SA103S box for your return or your accountant.
Hamster Premium
Do more with less admin
The free app does the logging, the estimate and the deadline reminders. Premium adds four things, grouped just as they are in the app.
Know what you really earn
- Profit per mile, hour and hustle
- Which days pay you best
- Where your income is heading this year
- Your hustles compared side by side
- Your income and tax, year on year
Stay ahead of tax
- A heads-up before key tax thresholds
- See how extra earnings change your tax
Less admin
- Add earnings from bank statement PDFsRolling out on Android
- Import Uber and Deliveroo CSV exports
- A photo on every logged expense
Ready to file
- An accountant-ready PDF for any period
- Your figures labelled with HMRC form boxes
Who it’s for
Made for the extra earners
Delivery and gig drivers
Uber, Deliveroo, Just Eat or Amazon Flex. Log trips and business miles as you go.
Online sellers
Vinted, eBay, Etsy or Depop, once selling becomes trading.
Freelancers and creators
Side gigs, tutoring, brand deals and content income.
Sole traders with a job too
Your side-hustle profit is taxed on top of your salary. Hamster works that out.
Not for everyone, yet: Hamster isn’t built for limited companies or partnerships. Its estimates use the Income Tax bands for England, Wales and Northern Ireland, and don’t include Scottish bands or student loan repayments. More on Hamster as a side hustle tax app and as a Self Assessment app for side hustlers.
Hamster is not affiliated with, endorsed by, or sponsored by Uber, Deliveroo, Just Eat, Amazon Flex, Vinted, eBay, Etsy or Depop. All trademarks are the property of their respective owners.
Free tool
Try the side hustle tax calculator
The same sum as the app, in your browser: your Income Tax and National Insurance for 2026–27, or the proposed 2027–28 rules, and what to set aside each month. No sign-up, and nothing you type is sent anywhere.
Open the calculatorPricing
Free to start
Hamster
Free
Log earnings, costs and miles, see your tax and National Insurance estimate and what to set aside, and get reminders before 31 January.
Hamster Premium
£4.99 a month
Yearly option available
14-day free trial on Android
All four Premium groups. Billed through Google Play; cancel any time in your store’s subscription settings.
Who is Hamster for?
Anyone in the UK earning on the side as a sole trader: delivery and gig work, selling online, freelancing or creating content, usually alongside a job. It isn’t built for limited companies or partnerships.
What does it cost?
The core app is free: logging earnings and costs, the tax and National Insurance estimate and what to set aside. Hamster Premium is optional, at £4.99 a month, yearly option available, billed through Google Play. 14-day free trial on Android. Cancel any time in your store’s subscription settings.
Is Hamster on iPhone?
Not yet. For now Hamster is on Google Play for Android. Tap “iPhone: email me when it’s live” next to the Google Play button and we’ll email you when it’s on the App Store.
Do I need to connect my bank account?
No. Hamster never asks for your bank login or open-banking access. You add earnings yourself, or with Premium you can import an Uber or Deliveroo CSV, or a PDF bank statement that Hamster reads on your phone (rolling out now on Android; not on iPhone yet). Nothing from the statement is uploaded.
Where is my data kept?
On your phone. There’s no account or login, and nothing you enter is sent to a server run by Hamster. Your tax figures never leave your device. Deleting the app deletes everything it stores.
Don’t miss 31 January
A reminder before the Self Assessment deadline
The deadline for your 2025–26 return is 31 January 2027. We’ll email you before it, with the occasional side-hustle tax tip.