UK Business Software
Everything your business needs.
Nothing it doesn't.
Calla Solo is live now — track your income, expenses and mileage, then submit your tax return in one click. From £6 a month.
No commitment. Cancel any time.
The Suite
Built for UK businesses
For sole traders and contractors. Track income, expenses, and mileage — then submit your SA100 in one click.
Double-entry bookkeeping, VAT returns, invoicing, expenses, and CIS — built for small UK businesses.
Client management, jobs, invoicing, AML, portal, and GoCardless billing for accountancy practices.
Statutory accounts, iXBRL filing to Companies House, CT600, and client approval with Yoti eSign.
UK-built
Designed for HMRC, Companies House & MTD
£6/mo
Solo — the most affordable way to stay compliant
No lock-in
Cancel any subscription any time, online
One login
All your Calla products, one account
Your tax return, sorted.
£6 a month.
No accounting knowledge needed. Track what you earn, log what you spend, record your mileage — then submit your Self Assessment in one click.
No commitment. Cancel any time.
Who Solo is for
Contractors
Invoice clients, log mileage to site, claim tools and equipment.
Freelancers
Track project income, software subscriptions, and home office costs.
Tradespeople
Scan receipts on the go, track mileage, know exactly what you owe HMRC.
Side hustles
Selling online, tutoring, childminding — Solo keeps it clean and simple.
Know exactly who owes you money
Send invoices to your clients in seconds. Solo shows you what's paid, what's waiting, and what's overdue — in plain English, not accounting jargon.
Got paper records? Import them here →
Bob Building Co
Due 25 Jul 2026
Waiting to be paid£400.00
They've paid ✓
📱 Tip: open Calla Pay and scan a receipt — it'll land here automatically. Got a spreadsheet? Import it →
Chaiiwala
2 Jun 2026 · Office and admin
Log what you've spent — scan or type
Photograph a receipt with Calla Pay and it fills itself in. Or type it manually. Solo works out what you can claim against tax automatically — no spreadsheets required.
HMRC mileage rate, calculated for you
Log each business journey and Solo does the maths. 45p per mile for the first 10,000, 25p after that — it tracks where you are and adds the claim to your tax return automatically.
This tax year
£393.30 you can claim
874 miles · 9,126 miles remaining at 45p
Land's End to John O'Groats
25 Jun 2026 · 874 miles · To drop off a package
Tax year 2025–26
Your Self Assessment
One button. Your tax return done.
At the end of the year Solo has everything it needs. It fills in your SA100, shows you exactly what you owe, and submits directly to HMRC. No accountant required.
- ✓ VAT threshold alerts at £75k, £85k, and £90k
- ✓ MTD quarterly reporting if you earn over £50k
- ✓ Import from any spreadsheet — any format
Your phone does the hard work
Calla Pay is the companion app included in your Solo subscription. Point it at any receipt and it reads the supplier, amount, date, and category — then sends it straight to Solo. No typing.
- ✓ Scan receipts with your camera
- ✓ Log mileage from your phone
- ✓ Works offline — syncs when you're back online
- ✓ Included in your £6/month — nothing extra
Point at a receipt
Simple pricing
£6/month
Everything included. No hidden extras.
- ✓ Invoicing — send and track
- ✓ Bills and expenses logging
- ✓ Mileage tracking with HMRC rates
- ✓ Calla Pay receipt scanning app
- ✓ SA100 Self Assessment submission
- ✓ VAT threshold alerts
- ✓ MTD auto-switch if you earn over £50k
- ✓ AI-powered spreadsheet import
Prices ex-VAT. Cancel any time.
Ready to stop dreading January?
Join sole traders and contractors who've sorted their tax for good.
Get Calla Solo — £6/monthFull double-entry bookkeeping, VAT returns, invoicing, expenses with HMRC category mapping, CIS, and bank reconciliation. Built for UK small businesses.
Client management, jobs, invoicing, AML compliance, client portal, document management, and GoCardless Direct Debit billing for accountancy practices.
Statutory accounts production, iXBRL direct filing to Companies House, CT600, management accounts, and Yoti eSign client approval. For accountancy practices already using Calla PM.
Full UK payroll — RTI FPS/EPS, auto-enrolment, P60, P11D, CIS contractor mode, and open banking salary payments direct to employees on pay day.
Download Calla Pay
Android APK — included free with your Solo subscription
Scan this code with your Android phone to download
Download APK directlyAndroid only. Enable "Install unknown apps" in your device settings.