Polytheseus · for bookkeepers and small practices

Fewer chasers. Fewer "why do I owe this?" emails.

Bookkeeper Skills turn ChatGPT, Gemini or Claude into an assistant that works like an experienced practice manager. Paste your notes or an export and get back a specific, dated records request, a suspense-account query list clients actually answer, or a plain-English explanation of a tax bill using the client's own numbers. You review it and send it.

Set it up free (5 minutes) See the Pro pack

For sole practitioners · small practices · in-house and freelance bookkeepers · UK and US
Works with: ChatGPT · Gemini · Claude · Microsoft Copilot (prompt pack) · Codex · Cursor · Gemini CLI · Claude Code

What it does with a messy suspense account

You paste five unexplained lines from a mixed-use sole-trader account (not VAT registered):

DateDescriptionAmountProposed
03/09FPS J SMITH−1,200.00ask wages, subcontractor, loan, personal? accountant payroll/CIS
05/09AMZN MKTP UK*2K4−86.40confirm supplies (medium)
05/09TESCO STORES 3301−42.17confirm personal (likely)
08/09TFR FROM M JONES+2,000.00ask sale, loan or capital? (never assumed to be sales)
12/09ADOBE *CREATIVE CLD−56.98high 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.

  1. 3 Sept, £1,200 to J Smith. Wages / subcontractor / loan repayment / personal / other?
  2. 8 Sept, £2,000 in from M Jones. A sale / a loan / your own money / other?
  3. 5 Sept, Amazon £86.40. We think this is supplies. OK, or what was it?
  4. 5 Sept, Tesco £42.17. We think this is personal. OK, or business?

For you

  1. Adobe: posted to Software, no question needed.
  2. J Smith: if it's labour, check payroll status. If it's construction, CIS applies.
  3. M Jones: hold in suspense until the client answers. Not sales by default.
  4. 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)

  1. Download the files. On the GitHub page, click the green Code button, then Download ZIP. Unzip it and open the chat folder.
  2. Create your assistant in the app you already use:
    • ChatGPT: GPTs → Create → Configure (or a ChatGPT Project).
    • Gemini: Gems → New Gem.
    • Claude: Projects → Create project.
  3. Paste everything in instructions.txt into the instructions box.
  4. Upload the three .md files as knowledge, then save.
  5. Try it: "Sole trader, plumber, 2025-26 return. Missing Monzo statements, van finance agreement, mileage. Asked once on 2 Oct. Draft the request."

Step-by-step instructions with every button named: SETUP.md.

Client data: 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 and your AI app's data settings.

Coding agents (Claude Code, Codex, Gemini CLI, Cursor, Copilot)

npx skills add polytheseus/bookkeeper-skills

Claude Code plugin: /plugin marketplace add polytheseus/bookkeeper-skills, then /plugin install bookkeeper@bookkeeper-skills. Manual paths are in the README.

Bookkeeper Skills Pro

All 8 skills, for the rest of the practice workload:

£24 · $29 · €27 one-off payment, free updates, single practice licence (up to 5 users)

Get Bookkeeper Skills Pro

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.