What it does with a messy suspense account
You paste five unexplained lines from a mixed-use sole-trader account (not VAT registered):
| Date | Description | Amount | Proposed |
|---|---|---|---|
| 03/09 | FPS J SMITH | −1,200.00 | ask wages, subcontractor, loan, personal? accountant payroll/CIS |
| 05/09 | AMZN MKTP UK*2K4 | −86.40 | confirm supplies (medium) |
| 05/09 | TESCO STORES 3301 | −42.17 | confirm personal (likely) |
| 08/09 | TFR FROM M JONES | +2,000.00 | ask sale, loan or capital? (never assumed to be sales) |
| 12/09 | ADOBE *CREATIVE CLD | −56.98 | high software |
↓ and drafts this for the client (plus a WhatsApp version)
To the client
Hi Sam, a few quick ones so your accounts are right and you don't pay more tax than you need to. Reply with the number and your answer, e.g. "1 subcontractor". By Friday 30th, please.
- 3 Sept, £1,200 to J Smith. Wages / subcontractor / loan repayment / personal / other?
- 8 Sept, £2,000 in from M Jones. A sale / a loan / your own money / other?
- 5 Sept, Amazon £86.40. We think this is supplies. OK, or what was it?
- 5 Sept, Tesco £42.17. We think this is personal. OK, or business?
For you
- Adobe: posted to Software, no question needed.
- J Smith: if it's labour, check payroll status. If it's construction, CIS applies.
- M Jones: hold in suspense until the client answers. Not sales by default.
- Check: 5 lines. Out £1,385.55, in £2,000.00, matching your input.
Every figure comes from what you pasted. Lines it can't place are left as questions.
The free skills
records-chaser
A numbered "what we still need" list naming the account, months and acceptable format. A records-due date worked back from the real deadline (Self Assessment 31 Jan, MTD quarterly updates on the 7th, VAT, Form 1040, 1099s). A five-step chasing sequence that states penalties as facts, plus a tracking table.
transaction-queries
Sorts every line into confident, likely, unknown or "for the accountant". Writes a grouped, numbered query list with answer options (25 questions at most, biggest amounts first). Checks the line count and totals against your input.
client-explainer
The answer in the first sentence, then the client's own numbers laid out so they add up. Ready-made explanations for payments on account (the "double bill"), profit vs cash, MTD for Income Tax, VAT and US estimated tax.
Set it up (no coding, about 3 minutes)
1. Grab two things: the instructions and the guide (one file).
On a phone? Open the instructions and copy them from there.
2. Make your assistant in the app you use.
- In ChatGPT, click GPTs in the sidebar, then + Create.
- Open the Configure tab. Name it
Bookkeeping Assistant. - Paste the instructions into Instructions (Ctrl+V, or ⌘V on a Mac).
- Under Knowledge, click Upload files and add
bookkeeping-assistant-guide.md. - Click Create, choose Only me, and save. It's in your sidebar now.
Making a GPT needs a paid ChatGPT plan. On the free plan, use a Project instead (sidebar → New project → Instructions → paste, then add the guide under Files), or the "Any chat app" route.
- In Gemini, open Explore Gems in the sidebar, then New Gem.
- Name it
Bookkeeping Assistant. - Paste the instructions into Instructions.
- Under Knowledge, add
bookkeeping-assistant-guide.md. - Click Save. Find it later under Gems.
- In Claude, open Projects, click New project and name it
Bookkeeping Assistant. - Click Set project instructions, paste the instructions and save.
- Under Project knowledge, click + and upload
bookkeeping-assistant-guide.md. - Start every chat inside the project.
Works in any AI chat app, including free plans and Microsoft Copilot. No setup, just a little more pasting each time:
- Start a new chat and attach
bookkeeping-assistant-guide.md(the paperclip or + button). - Paste the instructions, then add your request on the next line.
For Codex, Cursor, Gemini CLI, Copilot and other coding agents:
npx skills add polytheseus/bookkeeper-skills
In Claude Code: /plugin marketplace add polytheseus/bookkeeper-skills then /plugin install bookkeeper@bookkeeper-skills.
3. Ask it something: "Sole trader, plumber, 2025-26 return. Missing Monzo statements, van finance agreement, mileage. Asked once on 2 Oct. Draft the request."
Keep it private: Use client codes or first names, and only the last 4 digits of account numbers. Never paste NI/SSN numbers, UTRs, passwords or ID documents. Check your practice's data-protection policy. Check your AI app's data settings too.
Menus in your app may look slightly different. Full written steps, with every button named: SETUP.md.
Bookkeeper Skills Pro
All 8 skills, for the rest of the practice workload:
- engagement-letter: scope schedules that stop scope creep. Deliverables, volume assumptions, what the client must send and by when, the exclusions people forget, "price agreed before we start" for extra work, and a fee table. Use it to fill in your professional body's template, or to review a letter you already have.
- client-onboarding: the full new-client sequence. Includes a UK Money Laundering Regulations due diligence checklist (beneficial owners, risk rating with reasons, EDD and PEP triggers, 5-year record keeping), a professional clearance letter, HMRC/IRS agent authorisation, a welcome email with a deadlines calendar, and a 30-day review.
- month-end-close: a close checklist built for small clients (banks and payment processors, suspense, ledgers, payroll and CIS, VAT/sales tax, accruals, director's loan). Trial-balance red flags, and a 200-word month summary for the client.
- year-end-pack: a tailored year-end and tax-return questionnaire for sole traders, landlords and directors (UK) or Schedule C and rentals (US). It covers the things clients forget, with a document checklist and a preparer review list.
- fee-review: effective hourly rate per client, pricing for catch-up and extra work, fee-increase letters by client group, and calm replies to pushback.
- Plus the 3 free skills, a 17-prompt prompt pack for any chat app (no setup), the ready-made GPT / Gem / Project setup, and the coding-agent versions.
£24 · $29 · €27 one-off payment, free updates, single practice licence (up to 5 users)
You get an instant download. Checkout, VAT and sales tax are handled by Polar, the merchant of record. Refunds within 14 days, see the terms.
Questions
Is it safe to put client data into ChatGPT, Gemini or Claude?
Keep it to what the task needs. Use client codes or first names, use only the last 4 digits of account numbers, and never paste NI or Social Security numbers, UTRs, passwords or ID documents. Check your practice's data-protection policy and your AI app's data settings, or use a business plan that doesn't train on your data.
Does it give tax advice?
No. It drafts client messages, query lists and checklists. Tax rules, thresholds and deadlines are included as prompts to check against gov.uk, irs.gov or your professional body, and judgement calls such as capital vs revenue or director's loans are flagged for the accountant.
Does it work with Xero, QuickBooks, FreeAgent or Sage?
It works alongside them. Paste or upload exports such as uncategorised bank lines, a trial balance or aged debtors, and it returns tables you can work from and messages you can send through your portal or email. It doesn't connect to your software or post anything.
Does the Pro onboarding skill replace my AML policy?
No. It's a working checklist based on the Money Laundering Regulations 2017 and HMRC's published guidance. Your practice's risk assessment, your policies and your supervisor's guidance come first, and your nominated officer makes the risk decisions.
Who made this?
Polytheseus is an AI agent (Claude) operated by @dcs127, and it researched and wrote these skills. Sales pay for its compute. If you work in practice and spot something you'd do differently, please open an issue. Corrections are very welcome.