Claude for accountants and bookkeepers in New Zealand

Where Claude fits in a practice

Think of Claude as a fast, literate junior who has never met your clients. It reads a long PDF quickly, drafts a clear letter, explains a formula and spots that two lists do not match. It also states wrong things with confidence. Anthropic's own help centre says Claude can write things that look correct but are very mistaken, and that it should not be the only source for high-stakes decisions¹. A GST return, a set of annual accounts and advice to a client about tax are all high-stakes.

Anthropic's Usage Policy treats financial decisions and legal interpretation as high-risk uses. Where output gives advice or recommendations to individuals, it expects a qualified professional to review the content before it goes out, and, where its output is presented directly to the client, it requires the business to disclose that AI was used². For a chartered accountant or a bookkeeper, that review is already the job. The change is that it becomes explicit, and somebody signs off the draft that Claude wrote.

The good uses cluster in four places: reading source documents, finding exceptions in exports, drafting correspondence, and keeping firm knowledge in one place. The weak uses are the ones that ask Claude to supply a number that is not in front of it, or to decide how a transaction should be treated without the facts.

• Good: summarise a bank statement PDF into a table of unusual items for a human to code.
• Good: compare a client's sales listing with the GST return workpaper and list the differences.
• Good: turn a partner's dot points into a client letter in the firm's tone.
• Weak: ask what a client's GST position is without giving it the workpapers.

Set the account up before any client file goes in

The plan matters more than the prompt. On Free, Pro and Max, which are consumer plans, Anthropic asks each user whether their chats can be used to improve its models, and data is kept for five years if the user agrees, or 30 days if they do not³. Team and Enterprise are covered by Anthropic's commercial terms, which say Anthropic may not train models on customer content⁴. A practice holding client tax files should be on Team or Enterprise, not on staff members' personal accounts.

Team has a minimum of two members, and Anthropic's help page describes standard and premium seats with different usage allowances⁵. A practice of eight people can usually start on standard seats and move the heavy users later. Whoever owns the account also controls organisation settings, including which connectors staff can add⁶.

Under the Privacy Act 2020, the practice is the agency responsible for the personal information it holds, including what it sends to a service provider⁸. The Office of the Privacy Commissioner expects organisations to have senior leadership approve generative AI use, to assess privacy risk before they start, and to have a person review output before acting on it⁹. In a practice, that means a partner signs off the tool, the plan and a one-page rule for staff before the first client spreadsheet goes in.

• Buy Team or Enterprise seats in the practice's name.
• Tell staff to stop using personal Claude accounts for client work.
• Write a one-page rule: what may go in, what may not, and who reviews.
• Record the decision and the privacy assessment in the practice's compliance file.

Use Projects for firm knowledge, not as a client vault

A Project in Claude is a workspace with its own uploaded knowledge and its own instructions. You create one from the Projects page with the New Project button, add files with the plus button, and write standing guidance under Set project instructions¹⁰. On Team and Enterprise you can share a Project with colleagues as view or edit¹⁰.

Build one Project for the firm's own material: the engagement letter template, the standard management letter, the house style for client emails, a summary of the practice's review checklist, and a list of the questions you always ask at year end. Put an instruction at the top: write in New Zealand English, use the firm's sign-off, never state a tax figure unless it appears in the uploaded workpaper, and flag every assumption.

Be careful about one Project per client. A shared Project is visible to everyone it is shared with, so share a client Project only with that engagement team. For most small clients, a fresh chat with the relevant files, deleted after review, keeps the footprint smaller.

GST work: what to give Claude and what to check

GST in New Zealand is charged at 15%, and a business must register once its turnover reaches, or is expected to reach, sixty thousand dollars in a 12-month period^11,21. Returns are generally due on the 28th of the month after the period ends, with different dates for periods ending in November and March¹². Claude does not need to tell you any of that. Your team knows it, and the rules come from IRD, not from a chat.

Where Claude helps is the evidence. Since 1 April 2023, the old tax invoice rules have been replaced by taxable supply information, with lighter requirements for small supplies and buyer details needed only above a higher value threshold^13,22. Upload a batch of supplier invoices as PDFs and ask Claude to list, in a table, each supplier, date, GST-inclusive total, GST amount and whether the document shows the supplier's GST number. Then ask it to mark any invoice above that higher threshold that does not show the buyer's name. A human then looks at the marked items. Claude can read up to 20 files per chat, which suits a monthly batch¹⁴.

For a two-monthly return, a useful pattern is a reconciliation request. Export the GST report from the ledger and the sales listing, upload both, and ask Claude to explain every difference above a threshold you set. Ask it to quote the row it is relying on. Anthropic's guidance on reducing errors recommends exactly this: tell the model it may say it does not know, ask it to quote the source, and check the quotes¹⁵.

• Upload the source documents, not a summary of them.
• Ask for a table with one row per item and a column for the page or row reference.
• Ask Claude to list what it could not read, such as a blurred scan.
• Re-add the totals yourself in the ledger or in Excel before you rely on them.
• Never let Claude file anything in myIR or decide a zero-rating question.

Month-end review in Excel and Xero

Claude can create and edit Excel, Word, PowerPoint and PDF files when Code execution and file creation is switched on under Settings, then Capabilities¹⁶. Upload a trial balance export and last month's version and ask for a workbook with a variance sheet, a column for the percentage movement and a notes column. Open the formulas. If a formula is hard-coded, ask Claude to rebuild it so a reviewer can follow it.

Claude for Excel is an add-in for paid plans, installed from the Claude for Microsoft 365 listing in Microsoft AppSource¹⁷. It works inside the workbook you already have open. Anthropic's own page says it is not recommended for final client deliverables without human review, and it warns that a spreadsheet from an untrusted source can carry hidden instructions¹⁷. Treat a client's spreadsheet as untrusted until you have looked at it.

Xero has a connector listed in Claude's connector directory, described as read-only access to Xero financials from a conversation¹⁸. Staff add connectors under Customize, then Connectors, and on Team and Enterprise an owner decides which connectors the organisation allows⁶. Read-only is the right default. Start with the practice's own Xero organisation, test it for a month, and only then decide whether any client organisations should be reachable.

A hypothetical example. Imagine a bookkeeper in a ten-person Tauranga practice closing the month for a hospitality client. She exports the profit and loss for this month and the same month last year, uploads both, and asks Claude to list lines that moved by more than a set amount, with a one-sentence question to the client for each. She deletes the questions she can already answer from the bank feed, rewrites any that misread a reclassification, and sends the rest.

Client letters and IRD correspondence

Letter drafting is the most reliable win. Give Claude the facts in dot points, the firm's template from the Project, and the reader: a sole trader who is anxious about a penalty, or a director who wants two lines. Ask for a draft that says what happened, what the client must do and by when. Then check every date and amount against the IRD notice or the workpaper.

For a letter from Inland Revenue, upload it and ask Claude to explain it in plain English, list what IRD is asking for, and list the deadline it states. Ask it to quote the sentence that contains the deadline. That quote is the part you check. Do not ask Claude what IRD's policy is on remission or instalments and rely on the answer; read the IRD page and give the relevant text to Claude if you want it summarised for a client.

Engagement letters are a good Project task. Keep the approved version in the Project and ask Claude to tailor it for a trust, a look-through company or a new employer. A partner approves each variant once.

• Write the facts yourself; let Claude write the sentences.
• Check every date, amount and name against the source.
• Keep approved letters in the firm Project as the next template.
• Say in the engagement letter that the firm uses AI tools under staff review, if your privacy assessment calls for it.

Privacy, confidentiality and payment fraud

Client files contain personal information even when the client is a company: directors, employees on payroll, beneficiaries. The Privacy Act 2020 information privacy principles cover how that information is stored and protected, checked for accuracy before use, and disclosed, including to overseas services⁸. Claude is an overseas service. Anthropic's help pages say requests may be processed in other regions, and US-only processing is offered only on some Enterprise arrangements¹⁹. Your privacy assessment should say that plainly.

If something goes wrong, for example a staff member pastes a payroll file into a personal account, the Privacy Act requires an agency to notify the Privacy Commissioner and affected people as soon as practicable when a breach has caused or is likely to cause serious harm⁸. Put the steps in the practice's breach procedure now.

Payment fraud is the other risk. Business email compromise usually arrives as a convincing message asking to change bank details. The government's Own Your Online service advises people to confirm changed payment details through a separate, known channel and not by replying to the email²⁰. Claude makes it easier for criminals to write a convincing email, too. A rule that bank detail changes are confirmed by phone to a known number is worth more than any tool.

• Remove IRD numbers and bank account numbers from uploads unless the task needs them.
• Use an incognito chat for one-off questions that should not stay in history⁷.
• Delete chats that held client data once the work is reviewed.
• Confirm every change of bank details by phone to a number you already hold²⁰.

A first fortnight for a practice

Spend the first week on the firm's own work, not on client files. Build the firm Project, load the templates and write the instructions. Have each person try three tasks: one letter, one document summary and one spreadsheet comparison.

In the second week, pick one recurring client task, such as GST invoice checks for two-monthly filers, and run it with Claude alongside the normal process. Compare the exceptions Claude found with the ones your team found. Keep the method if it caught the same items or more. Drop it if the review took longer than the work.

• Plan chosen and in the practice's name.
• Training and data settings checked for every seat.
• One-page staff rule signed off by a partner.
• Firm Project built with templates and instructions.
• One client task trialled in parallel with the normal process.
• A partner reviews the trial before anyone uses it alone.