Claude for accounting: a practitioner's guide

Claude can walk you through an inherited workbook tab by tab and draft the commentary you would otherwise write at 11 p.m. in busy season. Here is what it costs, what Anthropic itself publishes for accounting work, what to keep out of it, the settings to check, prompts that fit a practice, and the part of client work it sees only if you bring it in.

This guide is for the accountant, CPA or tax preparer in a small firm or solo practice who is weighing Claude for client work. It is a companion to our wider map of AI for accountants, which surveys the tool landscape and the professional rules. Here the subject is Claude alone, checked against Anthropic's pages on 2026-10-01.

A word on who wrote this: Equerry, the personal assistant described near the end. Equerry keeps track of what you send it about each client; it never touches the ledger or the return, it has no Excel or tax-software connection, and it is not affiliated with Anthropic. Nothing here is tax, legal or professional advice.

What Claude costs an accountant

Claude is Anthropic's general-purpose assistant. From its pricing page (US, before tax, read 2026-10-01):

Anthropic's pricing FAQ: "Every plan has usage limits that reset on a rolling five-hour session window, and paid plans add weekly limits on top." The Excel add-in draws on the same pool. Free is enough to judge Claude's drafting on non-client material; the add-in starts at Pro. The plan comparison marks training "Opt-out" on Free, Pro and Max, so the choice is yours (the steps are below).

What Anthropic publishes for accounting and finance work

Claude for Excel

Anthropic's own Claude Academy has a tutorial for exactly this search, "How to use Claude in Excel for accounting: Revenue model validation." Its subject: "In this tutorial, you'll see how an accountant uses Claude to validate an ASC 606 revenue recognition model—the kind of multi-tab workbook you might inherit during an audit or acquire in a transaction." "Claude catches reconciliation gaps, duplicate entries, and missing data across multiple sheets." And it does not fix them on its own: "When Claude finds a problem, it shows you what's wrong, explains the recommended fix, and waits for your go-ahead."

Anthropic's documentation: "Claude for Excel is generally available to Pro, Max, Team, and Enterprise plans." It runs in Excel on the web, on Windows with a Microsoft 365 subscription and on Excel on Mac version 16.46 or later, not on Excel for iPad. Under current limitations, Anthropic does not recommend it for "Final client deliverables without human review," "Audit-critical calculations without verification," or "Models containing highly sensitive or regulated data without proper controls." It also says: "Only use Claude for Excel with trusted spreadsheets." Its reason: "Files from external sources can contain hidden instructions that manipulate the add-in into extracting data, modifying records, or performing destructive actions." A workbook a client emails you is a file from an external source.

In words: on Microsoft AppSource, open the Claude for Microsoft 365 listing and select "Get it now"; then open Excel, activate the add-in, and sign in with your Claude account.

The Finance plugin, and who it is built for

Anthropic's marketplace lists an "Anthropic verified" plugin named Finance: "Streamline finance workflows: journal entries, reconciliation, financial statements, and variance analysis." Its source README, titled "Finance & Accounting Plugin," adds month-end close and SOX audit support, through commands such as /journal-entry and /reconciliation. It is "primarily designed for Cowork, Anthropic's agentic desktop application," and on September 16, 2026 Anthropic wrote: "Starting today, Claude Cowork and chat are merging into one Claude." That merger is "rolling out on Pro and Max plans over the next few weeks, with more plans to follow." The README's warning: "All outputs should be reviewed by qualified financial professionals before use in financial reporting, regulatory filings, or audit documentation."

The commands read as built for a controller's team closing the books in an ERP such as NetSuite or SAP, which the README names. Claude for Financial Services, Anthropic's separate offering, serves "financial institutions across banking, insurance, asset and wealth management, and fintech"; its newest part, Claude for financial advisors, sits under the heading "Built for how RIAs run." Our reading: neither is built for an accounting practice.

One page speaks to your clients rather than to you. Anthropic's small-business page says: "Claude closes the books, forecasts cash, prepares payroll, creates reports, and has your Monday brief waiting before you ask. You make the calls and sign off." Its sample month-end prompt ends: "I want the packet ready for my accountant by Tuesday." If a client sends you a packet like this, review it as you would any client-prepared schedule.

Where Claude saves an accountant time, and where it falls short

• The inherited workbook. A prior preparer's model or a client's forecast: how the tabs connect and where a figure comes from.
• Commentary. Variance and flux explanations drafted from balances you supply, with you supplying the reasons.
• Tie-outs on a copy. A trial balance against last year's workpapers, or a lease or fixed-asset schedule explained tab by tab.
• Reconciliation exceptions. The Finance plugin's marketplace page: "Use /reconciliation to compare GL balances to subledger, bank, or third-party balances and identify reconciling items."

The limits are as specific. Figures: a number Claude states in chat is unverified until you tie it out. Authority: a code section or threshold it gives from its own knowledge must be checked at the source. The client: Claude knows the engagement only through what you type, paste, upload or connect. Memory: Anthropic says "Some information is never saved to memory, even if you ask," naming government ID numbers and financial account numbers among it. That keeps them out of memory, not out of the chat, which keeps what you pasted until you delete it.

Client data in Claude, from engagement letter to file close

What goes into Claude changes as an engagement moves, so set it up in that order. Anthropic's controls below are quoted from its help and privacy centers, read 2026-10-01. These are cautious defaults; your firm's policy decides.

Before the first file arrives

• Choose the training setting once. The path is the same on the web and on mobile: your name in the settings menu, then Settings, then Privacy. Anthropic's Privacy Center (article dated August 3, 2026): "Under Help Improve our AI models, click the button to toggle it off/on." Once it is off, Anthropic "will not use any new chats and coding sessions you have with Claude for future model training."
• Open a Project for the client. "Each project has its own separate memory space and dedicated project summary." Free gives you 5.

During the work, by type of material

• Workbooks: a dummy copy, or one stripped of names and identifiers. A vendor list, a payroll total and an industry can still point to one client.
• Statements and payroll: bank and brokerage statements, payroll registers, Social Security and employer identification numbers stay out until your policy and, where required, the client agree.
• Return information: the IRS's Section 7216 information center (updated 07-Sep-2026) says: "Final Treasury Regulations on rules and consent requirements relating to the disclosure or use of tax return information by tax return preparers became effective Dec. 28, 2012." Check how they apply before any return information goes into Claude or any other tool.
• Public text and your own templates: standards, IRS publications and checklists, as long as they carry no client details.
• A one-off question: before the first message, open "+" and switch "Memory" off. Anthropic (help center, updated 2026-09-30): "Claude won't use what it remembers about you in that chat, and nothing from the chat is saved to memory." The chat stays in your history, and the switch works in Projects. To keep a chat out of history as well, the ghost icon outside a Project opens an incognito chat, which Anthropic says is not used for training; its stated retention is "30 days (default), or longer" under an Enterprise organization's own setting.

When the engagement closes

• Delete the chats. Anthropic: "Removed from your chat history immediately" and "Deleted from our back-end storage systems within 30 days."
• Then the memory. "When a conversation expires or is deleted, related memory entries generated from it won't be removed." In Settings → Memory, everything Claude remembers "is listed under Topics": open each one about the client and delete it.

Prompts for client work

Each works on dummy data or material you are cleared to share. Check every figure before anything leaves your desk.

• The inherited model (Excel add-in). Anthropic's own opener: "Walk me through this model. What's on each tab and how does everything tie together?" Follow with: "List every hardcoded number that feeds a total, with its cell, and every place two tabs disagree about the same figure."
• Flux commentary. "Here are this month's and last month's balances by account, client name removed. Draft commentary for each line that moved more than 10% and $5,000. Where the numbers don't tell you why, write the question I should ask the client instead of a reason."
• The prior-year tie-out (Excel add-in). "Compare the trial balance on this tab with last year's workpaper tab. List every account whose opening balance doesn't match the prior-year closing balance, with both cells."
• The fixed-asset schedule. "Walk me through the depreciation tab: the method for each asset class, where the useful lives come from, and any row whose formula differs from its neighbours."

None of them can tell you what the client said on last week's call.

Outside Claude: the record of each engagement

Anthropic's help center: "Claude can generate memory based on your chats." That is good for remembering how you like a variance note written, not for being the record of an engagement. Nothing arrives on its own. A CFO's answer on a call exists in Claude once you type it; a client's email about late 1099s, once you paste it or connect its account. Connecting goes wide: Anthropic's documentation says Claude for Excel shares context with Claude for PowerPoint, Word and Outlook, "so a single conversation can span your open workbook, presentation, document, and inbox." How far any tool should reach into client information is the decision our map of the accounting AI landscape asks you to make with your firm.

A note after every call and a client-owes list keep that record without AI. The weak point is finding it in March, after a later reply changed it.

An assistant for the client side: Equerry

Equerry is a personal assistant who helps you get things done. For an accountant that means the client record around the numbers. It doesn't prepare returns, post entries or open workbooks.

• CC or forward the engagement thread. Equerry has its own address at mail.getequerry.app. Forward it a thread as it stands, or put it on the CC line of a live one so later replies keep arriving for as long as the address stays on the thread. It never asks for access to your inbox; the original stays where it is, in your mailbox. What Equerry remembered from it is listed in Settings → Your memory, each line marked as from that email, and you can delete any line.
• Talk through the call afterwards. Record a voice note in Equerry: the CFO's answer on the accrual, the schedules you promised, the documents still owed. Equerry transcribes it to answer from later. Equerry does not join, record or place calls.
• Send the PDF, not the workbook. From your iPhone's share sheet, send a PDF, a photo of a notice or a screenshot. The share sheet takes PDFs, images, links and text; spreadsheets stay where they are.
• Type a note. When an answer draws on a note you saved, it carries a source chip: tap it to see the passage Equerry used and open the original.
• Ask in busy season. "When did the client say the inventory count would be ready?" is answered from the threads, notes and voice notes you gave it.
• Prepare for the year-end meeting. If you allow calendar access and set up Meeting Prep, Equerry puts together where things stand with that client from what you have shared.

Where it stops: Equerry works from what you send it, plus your calendar if you allow it, so a client reply you never forwarded is out of its reach. Its address shows on the CC line to everyone on the thread. Whatever you send is processed to make it searchable and answerable, including by the outside providers named on our AI disclosure page. Equerry makes no claim about any professional or tax rule, and the §7216 check above covers return information sent to Equerry as much as to Claude. The difference is reach: one engagement thread and one note at a time, never a whole mailbox.

If your practice also runs on ChatGPT, see ChatGPT for accountants; for how the same tool looks in a law practice, Claude for lawyers.

Sources, all read 2026-10-01. Anthropic: Claude pricing (prices exclude applicable tax; "Price and plans are subject to change at Anthropic's discretion"); Claude Academy, How to use Claude in Excel for accounting: Revenue model validation; Use Claude for Excel (documentation); Claude Marketplace, Finance plugin, and its source README; Claude for financial services; Claude for small business; Claude Cowork and chat are now one Claude (September 16, 2026). Claude Help Center: Use Claude's chat search and memory to build on previous context (updated 2026-09-30), Use incognito chats (updated 2026-09-30). Anthropic Privacy Center: How do I change my model improvement privacy settings? (dated August 3, 2026), Is my data used for model training?, How long do you store my data? Internal Revenue Service, Section 7216 information center (updated 07-Sep-2026). Anthropic's privacy articles describe consumer plans (Free, Pro, Max) unless they say otherwise. Anthropic updates these pages often; if its current page disagrees with this one, trust Anthropic's. This guide is general information, not tax, legal or professional advice.

Last updated 2026-10-02.

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