For UK sole traders

Jobs clear,
money clear.
Every day.

A simple business tracking system built in Google Sheets. See every job, every quote and everything you're owed — all in one place. No software to learn, no subscription, no data going anywhere but your own Google account.

See how it works Buy Plain Systems ↓
Built in Google Sheets One-time purchase · £89 Your data, your account Not accounting software

A note on Plain Systems

"I built this to fix my own problem. I was losing track — an invoice sent and forgotten, a quote that went quiet, a job finished but not yet charged. My weekends were getting eaten up trying to organise my work. So I built a sheet to keep all of that visible. It worked well enough that I thought other people might want it too. Nothing more complicated than it needs to be."

James · Plain Systems

How it works

Open it in the morning. It tells you what needs doing.

Seven sheets cover the full picture — today's priorities, live jobs, open quotes, outstanding money, overdue invoices, expenses, and your MTD position. Switch between them to explore.

Today
Thu 12 Mar · 4 jobs need attention
S. Clarke — Boiler service
Invoice sent 18 Feb · 22 days overdue
£680
Overdue
T. Patel — Bathroom refit
Week 2 of 3 · In progress
£2,400
Active
M. Hughes — Leak repair
Invoice sent 1 Mar
£195
Sent
R. Okafor — Full installation
Starting 14 Mar · Booked
£3,100
Booked
J. Marsh — Service call
Paid 4 Mar
£320
Paid
Overdue
£680
Outstanding
£875
Jobs
6 active jobs · £7,020 total
R. Okafor — Full installation
Starting 14 Mar
£3,100
Booked
T. Patel — Bathroom refit
Week 2 of 3
£2,400
Active
D. Singh — Unit swap
Quote sent · Awaiting
£1,200
Quoted
J. Marsh — Service call
Complete · Paid 4 Mar
£320
Done
In progress
£5,500
Quoted
£1,200
Quotes
5 open quotes · £8,100 value
P. Osei — Full refurb
Sent 28 Feb · No reply yet
£3,800
Chase
D. Singh — Unit swap
Sent 3 Mar
£1,200
Awaiting
R. Okafor — Full installation
Accepted · Job booked
£3,100
Won
Open value
£5,000
Won this month
£3,100
Money
March 2026 · Updated today
J. Marsh — Service call
Paid 4 Mar
£320
Paid
M. Hughes — Leak repair
Invoice sent 1 Mar
£195
Awaiting
S. Clarke — Boiler service
Invoice sent 18 Feb
£680
Overdue
Paid this month
£320
Still owed
£875
Overdue
2 invoices overdue · £875 owed
S. Clarke — Boiler service
Invoice sent 18 Feb · 22 days
£680
Overdue
M. Hughes — Leak repair
Invoice sent 1 Mar · 11 days
£195
Overdue
Total overdue
£875
Oldest invoice
22 days
Expenses
March 2026 · Costs logged
Parts — T. Patel job
Materials · 6 Mar
£142
Materials
Van fuel — week of 3 Mar
Travel · 7 Mar
£68
Travel
Public liability renewal
Insurance · 1 Mar
£220
Insurance
This month
£430
This tax year
£2,840
MTD Readiness
Tax year to date · Apr 2025 – Mar 2026
Income received
Cash basis · paid invoices only
£28,400
On track
Allowable expenses
From Expenses sheet
£6,210
Logged
Net profit (est.)
Income minus expenses
£22,190
Estimated
Quarter deadline
7 May
Days remaining
56

Who it's for

Built for one kind of business.

Plain Systems is specific by design — it does one thing well, for one kind of person.

A good fit if you are…
Sole trader · Google account · Working in the UK
✓A sole trader running your own jobs
✓Managing 3–20 jobs at any one time
✓Chasing invoices, tracking quotes, staying on top of money
✓Using a free Google account (Gmail is enough)
✓Wanting something simple you can open every morning
✓Preparing for Making Tax Digital from April 2026
Not the right fit if you…
Plain Systems is specific — it may not suit every business
✕Run a larger business with multiple staff or employees
✕Need to issue VAT invoices or manage VAT returns
✕Want software that files to HMRC automatically
✕Prefer working in Excel rather than Google Sheets
✕Are looking for a full accounting platform

What's included

Seven sheets. One system. All pre-built.

You don't set anything up from scratch. Open it, enter your jobs, and it works. Every sheet is already built — formulas, layouts, everything.

01
Today
Every active job sorted by urgency. Overdue invoices and jobs needing attention surface automatically. Open it each morning — it does the sorting for you.
02
Jobs
Add and update every job here. Quoted, booked, in progress, invoiced, paid — every status tracked in one place from first contact to final payment.
03
Quotes
Log every quote with its value, status and date sent. See what's open, won, or needs chasing — so nothing falls through the gap between quote and job.
04
Money
What you've been paid, what's outstanding, what's overdue. Running totals update when you log a payment. No manual adding up.
05
Overdue
A dedicated view of unpaid and overdue invoices. Sorted by age so you always know what to chase first and how long it's been outstanding.
06
MTD Readiness
A live view of your income, expenses and estimated net profit for the current tax year and quarter. Keeps your records in the shape your accountant needs for MTD submissions.
07
Expenses
Log costs as you go — materials, travel, tools, insurance. Categorised for your accountant and feeds directly into the MTD Readiness sheet.

Also includes a step-by-step written setup guide. Most people are up and running within 30 minutes.

Getting started

Up and running in 30 minutes.

No technical knowledge needed. If you can type into a spreadsheet cell, you can use Plain Systems.

01
Buy and receive your copy
After purchase, a copy of the system is delivered directly to your Google Drive. Nothing to install or download — it opens straight in your browser.
02
Open Settings and enter your details
Enter your name and business details once. The written setup guide walks you through every step clearly, in plain language. Takes about five minutes.
03
Add your current jobs
Enter your live jobs into the Jobs sheet. Today, Money, Overdue and Quotes all update automatically — nothing to calculate or cross-reference.
04
Use it every morning
Open it, check Today, log any payments or new jobs. That's the whole habit. Most people spend less than five minutes on it each day.

Plain Systems vs your accountant

Two different jobs. Both necessary.

Plain Systems is not accounting software and it doesn't replace your accountant. It fills the gap between finishing a job and your accountant seeing clean, organised numbers.

Plain Systems
Day-to-day control
□Keeps all your jobs visible — active, booked, overdue
□Shows exactly what you're owed right now
□Tracks every quote from sent to won or lost
□Logs expenses per category as you go
□Shows your MTD position for the current tax year
Does not connect to or submit anything to HMRC.
Your accountant + software
Tax, filing, year-end
→Files quarterly MTD returns to HMRC
→Submits your annual self-assessment
→Advises on allowances and tax treatment
→Uses Xero, QuickBooks or similar
→Needs your records tidy and readable
Sits alongside Plain Systems, not instead of it.

Pricing

One price. No subscription.

Buy once and use it for as long as you like. No monthly fees, no renewals, no catch.

Plain Systems
£ 89
One-time purchase · No subscription
Today · Jobs · Quotes
Money · Overdue
Expenses
MTD Readiness
Written setup guide
Buy Plain Systems
Built for Google Sheets. Not compatible with Excel.
Delivered directly to your Google Drive after purchase.
30-day refund if it doesn't work for you — no questions asked.
What you need
—A Google account (free — Gmail counts)
—Google Sheets (free, works in any browser)
—About 30 minutes for initial setup

No technical knowledge needed. The written setup guide walks you through it clearly, step by step. Most people are up and running the same day.

Common questions

Straightforward answers.

No. If you can type into a cell and press Enter, you can use Plain Systems. Everything is pre-built — no formulas to write, no layouts to set up. The written setup guide walks you through the 30-minute setup clearly and simply.
No. Plain Systems is built specifically for Google Sheets and uses features that don't transfer to Excel or LibreOffice. You need a free Google account to use it — most people already have one through Gmail.
No. Plain Systems is a job and money tracking system — built for day-to-day control, not accounting. It doesn't connect to HMRC, handle VAT returns, or replace your accountant or software like Xero. It keeps your records clean and visible every day, so your accountant has what they need when they need it.
Your data lives entirely in your own Google account — in your Google Drive, under your control. Plain Systems has no server, no database, and no access to your files after purchase. If you stop using it, your data stays exactly where it is.
No. Plain Systems does not connect to HMRC and submits nothing on your behalf. It helps you keep the records your accountant needs to handle your submissions. All HMRC interactions are handled by your accountant or MTD-compatible software.
Making Tax Digital for Income Tax is now rolling out for many sole traders from April 2026. Plain Systems doesn't file to HMRC — but the MTD Readiness sheet keeps your income and expenses organised by tax year and quarter, so your accountant has exactly what they need to handle your submissions. Think of it as keeping your side tidy.
Yes. If Plain Systems doesn't work for you for any reason, email within 30 days of purchase for a full refund. No questions asked.

Free resource · MTD for ITSA

Not sure if MTD affects you?
Start here.

A one-page PDF covering key dates, what records you need to keep, and one practical action to take this week. Free — no fluff, no sales pitch.

No spam. One email with your PDF. Unsubscribe any time.