UK Business Software
Everything your business needs.
Nothing it doesn't.
Calla Solo is live now — track your income, expenses and mileage, and get a complete report for your tax return. From £10 a month.
No commitment. Cancel any time.
The Suite
Built for UK businesses
For sole traders and contractors. Track income, expenses and mileage, then get a complete SA100 report to file or hand to your accountant.
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.
Full RTI payroll, auto-enrolment, P60/P11D, and salary payments straight from your bank by open banking. Launching soon.
AML compliance for accountancy practices — client risk assessments, identity checks, and the firm-wide risk register.
Register interestJob scheduling, engineer check-in, RAMS, parts and certificates — on a tablet, in the van, offline.
Register interestTablet till for the counter — takes card payments and posts every sale straight into your books. Comes with Calla Accounts, because it keeps the books it writes to.
Register interestUK-built
Designed for HMRC, Companies House & MTD
£10/mo
Solo — the most affordable way to stay compliant
No lock-in
Cancel any subscription any time, just ask
One login
All your Calla products, one account
Your tax return, sorted.
£10 a month.
No accounting knowledge needed. Track what you earn, log what you spend, record your mileage — then get a Self Assessment report laid out box by box, ready to file. Direct submission to HMRC is coming soon.
No commitment. Paid by Direct Debit. 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. When one goes unpaid, Solo chases it for you: friendly first, then firm, then final.
Got paper records? Import them here →
Bob Building Co
Due 25 Jul 2026
Waiting to be paid£400.00
They've paid ✓
Log what you've spent — scan or type
Photograph a receipt with Calla Pay and it fills itself in. Or type it manually. Keep a paper cash book? Photograph a page and Solo reads the rows in — anything it is unsure of waits for you to confirm. It works out what you can claim against tax automatically.
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
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
Your tax return, worked out for you.
At the end of the year Solo has everything it needs. It fills in your SA100 figures box by box, shows you exactly what you owe, and gives you a report to file with HMRC or hand straight to your accountant. Filing from inside Calla is coming once HMRC approve us.
- Your VAT return worked out, on the Flat Rate Scheme
- VAT threshold alerts at £75k, £85k, and £90k
- Your four MTD quarterly figures, with the deadlines
- Import from any spreadsheet — any format
Tax year 2025–26
Your Self Assessment
Your phone does the hard work
Calla Pay is the companion app included in your Solo subscription — you will find it in Solo under Settings. 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 £10/month — nothing extra
Point at a receipt
Simple pricing
£10/month
Everything included. No hidden extras.
Or £100 a year — two months free.
- Invoicing — send and track
- Bills and expenses logging
- Mileage tracking with HMRC rates
- Calla Pay receipt scanning app
- SA100 Self Assessment report, box by box
- Flat Rate VAT return, worked out for you
- VAT threshold alerts
- MTD quarterly figures and deadlines
- Chase unpaid invoices automatically
- Paper cash book? Photograph it and import
- AI-powered spreadsheet import
Prices ex-VAT. Paid by Direct Debit. Cancel any time.
Please sign up with the same email address you pay with — that is how we find your subscription.
Ready to stop dreading January?
Join sole traders and contractors who've sorted their tax for good.
Full double-entry bookkeeping, VAT returns, invoicing, expenses with HMRC category mapping, CIS, and bank reconciliation. Built for UK small businesses.
Register your interestClient management, jobs, invoicing, AML compliance, client portal, document management, and GoCardless Direct Debit billing for accountancy practices.
Register your interestStatutory accounts production, iXBRL direct filing to Companies House, CT600, management accounts, and Yoti eSign client approval. For accountancy practices already using Calla PM.
Register your interestFull UK payroll — RTI FPS/EPS, auto-enrolment, P60, P11D, CIS contractor mode, and open banking salary payments direct to employees on pay day.
Register your interest