Bookkeeping, tax and CPA practices of 10 to 50 people run QuickBooks Online Accountant or similar, a practice-management tool, Microsoft 365 or Google Workspace, and a client portal. AI pays here more than in most trades, because the work is reading and writing. Month-end summaries and client emails drafted from the ledger. Engagement letters checked against your template. Document requests chased automatically. Claude, ChatGPT and Microsoft Copilot all sell business seats at about $20 to $25 a month. Ignore any tool that posts entries or files anything without a reviewer, and any vendor that will not state in writing how client data is used.