The "Instructions for Claude" field is one of the highest-leverage things a finance leader can set up, because it applies to every conversation automatically. For a CFO the stakes are different than for most users: the cost of a confidently wrong number is high, and most of the output ends up in front of a board, a lender, or an auditor. Here is how to tune it for accuracy, defensibility, and executive polish, with a paste-ready template you can adapt today.
Most people treat the instructions field as a place for style notes. For a CFO it is closer to a standing operating procedure. Claude reads it before every task, so a few well-chosen lines quietly raise the quality of board decks, variance commentary, investor updates, and models without you re-explaining yourself each time.
The goal is not to write more. It is to write the right things: who you are, how you want numbers handled, what you produce regularly, and where Claude should stop and ask rather than guess. Get those four areas right and almost everything else takes care of itself.
Each of these earns its place in a short, half-page instruction. Together they cover context, accuracy, output, and judgment.
State your title, company stage, size, industry, and accounting framework up front. "CFO of a Series B B2B SaaS company, roughly 120 employees, US GAAP, calendar fiscal year" tells Claude more than three paragraphs of tone notes.
This is the single most important section. Tell Claude to never fabricate or estimate figures silently, to state every assumption, to show its math, and to ask for missing data rather than guessing. One instruction that prevents the most damaging failure mode.
List the things you actually produce: board decks, variance commentary, investor updates, cash flow forecasts, models. Claude picks up the conventions you imply and applies them without being re-prompted each time.
Output for an audit committee reads differently than a note to your CEO. Set the default audience so Claude calibrates detail and language. Most CFOs want concise, executive-level prose with the conclusion stated first.
Make clear that Claude should flag uncertainty, separate fact from inference, and not present output as professional accounting, tax, or legal advice. You want a fast, capable analyst, not false confidence.
Formatting preferences matter, but they are the least important part. A few lines on tables, length, and things to avoid is plenty. Put them at the end so they never crowd out the substance above.
Replace the highlighted placeholders with your own details and paste this into your "Instructions for Claude" field. It is deliberately compact: a focused half-page beats two pages Claude has to weigh against your actual prompt every time.
I'm the CFO of a [stage] [industry] company with roughly [N] employees. We report under [US GAAP / IFRS], our fiscal year is [calendar / ends June 30], and we operate primarily in [USD].
I mainly use Claude for FP&A, board and investor materials, variance analysis, cash flow forecasting, financial modeling, and internal memos to the executive team.
How to handle numbers: never invent, estimate, or round figures without telling me. State every assumption explicitly. Show your calculations when you compute anything. If you're missing data you need, ask me for it rather than guessing. Distinguish clearly between figures I gave you and figures you derived.
Audience and tone: default to a senior, executive-level reader (board, leadership team, or lenders). Lead with the conclusion or the so-what, then support it. Be concise and direct. Flag any material uncertainty rather than smoothing over it.
Conventions: present variances as favorable or unfavorable with the dollar and percentage change. Note materiality where relevant. You are not a substitute for professional accounting, tax, or legal advice, so caveat anything that crosses into that territory.
Formatting: use clean tables for financial data, prose for analysis and commentary, and keep it tight.
The copy button copies clean text with the placeholders intact, so you can paste it anywhere and fill in the brackets.
Resist the urge to make it long. A focused half-page beats two pages of detail that Claude has to weigh against your actual prompt every time. Avoid contradicting yourself, for example asking for both "brief" and "comprehensive" without saying when each applies. And revisit it every month or two as you learn what Claude tends to get wrong for you.
Do not instruct Claude to "be a CFO," or to act as any other specialty. It is tempting to open with "You are a CFO" or "act as an expert accountant," but a persona label adds no knowledge Claude does not already have, and it can quietly work against you. Role-play framing pushes the model toward sounding the part, confident, decisive, and authoritative, which is the opposite of what finance work needs. You want stated assumptions and honest uncertainty, not a character performing expertise. The signal that actually moves quality is the context you already gave, that you are the CFO and what your company looks like, plus clear standards for the output. Describe who you are and how you want the work done, and leave the persona out of it.
The best instructions are written after a few hundred real conversations, not before the first one. Start with the template, then refine it as you notice patterns in what you keep correcting.
Explore the live tools and prompt libraries built to help finance leaders get more out of AI, or reach out with a workflow you want to sharpen.