ChatGPT for finance: examples, prompts and controls
ChatGPT can help a finance team comment on a budget, prepare document requests and analyse files using calculation tools. Reliability depends on the supplied data, checks and context: fluent language does not prove a figure is correct.
English version published on 2 October 2026. Sources rechecked on the same date. The corrected teaching kit was added to the French guide on 30 September 2026.
How do you comment on a budget-to-actual variance?
This fictitious example uses thousands of euros. Expenses are positive amounts; the balance is a simplified difference, not accounting EBITDA.
| Indicator | Budget | Actual | Actual − budget variance |
|---|---|---|---|
| Revenue | 200 | 180 | −20 (−10%) |
| Expenses | 150 | 155 | +5 (+3.33%) |
| Simplified balance: revenue − expenses | 50 | 25 | −25 (−50%) |
Prompt to adapt:
Using this fictitious table in k€, write commentary of no more than 120 words. Use the calculated variances. Separate facts, hypotheses and questions to ask. Do not invent any cause or missing data. End with two questions for the sales lead and the expenses owner.
Expected answer: note that lower revenue and higher expenses reduce the balance. A lost customer, a salary increase or seasonality must remain hypotheses until documented. A percentage with a zero budget must be marked as not calculable.
The data model and upstream controls are explained in the automated reporting guide.
How do you prepare a more precise document request?
Provide the expected document type, period and exact reason for rejection. Remove unnecessary identifiers before testing. The Armanino case published by Anthropic describes a tool for drafting explanations when an audit document is incorrect.
Write a courteous request of fewer than 100 words. Document received: June trial balance. Document expected: July trial balance after closing. Explain the difference and specify the document to send. Add no amount, deadline or commitment that has not been provided.
Check the recipient, document and period before sending. This draft must not automatically trigger a follow-up. The case details and limitations distinguish the deployed tool from the benefits estimated by the publisher.
How do you prepare board questions?
Work from an approved reporting version after access has been authorised. Define the decision to prepare: recruitment, funding or expenditure trade-offs.
Using only the supplied indicators and commentary, suggest five questions a board member could ask. For each, cite the row or passage that motivates it, identify missing information and distinguish an observed risk from a hypothesis. Recommend no decision without the necessary data.
Compare the questions with the cash-flow forecast. Positive profitability does not rule out a short-term financing need.
Can ChatGPT calculate and analyse an Excel file?
Yes: OpenAI’s data-analysis documentation describes file analysis and code use. Distinguish generated prose from a calculation executed by a tool. Request the code or formulas, columns used and exclusions.
Check totals, signs, currencies, empty rows and duplicates separately. Rerun the calculation in Excel, a controlled script or BI. The presence of code validates neither assumptions nor file quality. Do not delegate account sign-off, payment approval or a tax decision to a model’s answer.
Which data and plan should you use?
Start with fictitious or public data. For internal data, the company must authorise the tool, its access and the processing purpose. Removing a name is not always enough to anonymise a file: amounts, dates and job roles may identify someone.
OpenAI documents no training by default on Business, Enterprise and API data. This does not mean no retention or permission to upload every document. Also check permissions, retention periods, connectors and contractual terms. DPO or security-owner approval depends on the company’s context.
Record authorised uses, excluded data, the reviewer and error procedures in your policy. Use our LLM selection framework to compare environments on your own documents.
Try fictitious reporting with its answer key
This teaching kit contains no client data. It describes one month for a fictitious company, in thousands of euros, with positive expenses. The revenue-minus-expenses balance is not accounting EBITDA.
Download the complete kit (ZIP) or open the CSV file.
- Open the data in Excel or your spreadsheet: semicolon delimiter, UTF-8 encoding. Check period, entity, unit and unique identifiers.
- Aggregate revenue and expenses, then calculate variances. Compare with the supplied answer key.
- Use the prompt below on this fictitious file. Reject any cause absent from the data.
- Then test the file containing a duplicate: the control must identify the repeated row before validating the total.
| Indicator | Budget | Actual | Variance |
|---|---|---|---|
| Revenue | 200 | 180 | −20 (−10 %) |
| Expenses | 150 | 155 | +5 (+3.33%) |
| Simplified balance | 50 | 25 | −25 (−50 %) |
Analyse this fictitious reporting in k€. Check duplicate identifiers, periods, units and empty fields before any calculation. If an anomaly exists, identify it and suspend validation of totals. Otherwise, calculate revenue, expenses and the simplified balance, then their budget variances. Show the operations or code used. Write commentary of no more than 120 words, separating facts, hypotheses and questions. Invent no cause. A percentage with a zero budget is not calculable.
Reference commentary: revenue is €20k below budget and expenses exceed budget by €5k. The simplified balance therefore falls by €25k. The data does not allow attribution to price, volume or hiring: these causes must be checked with the owners.
Passing this exercise does not validate deployment on your accounts. The pilot protocol describes controls to organise with your team.
Frequently asked questions
Can ChatGPT be used for a cash-flow forecast?
It can help structure assumptions and prepare calculations using tools. Due dates, expected receipts and scenarios must be documented, then verified in the reference financial model.
Does a paid plan guarantee confidentiality?
Price alone is insufficient. Check the plan’s contract, settings, retention, access and integrations, and comply with company policy.
Do these prompts describe Iter Advisors assignments?
No. The exercises use fictitious data. Public cases are attributed to their publishers and kept separate from documented Iter assignments.
Scope your project with a CFO
Share your needs, tools and difficulties. We can clarify the scope, deliverables and controls for support.
Discuss my projectSources & references
- Data analysis with ChatGPT — OpenAI Help Center, source rechecked on 2 October 2026.
- Business data protection — OpenAI, source rechecked on 2 October 2026.
- Armanino: drafting document requests — Anthropic / Claude, source rechecked on 2 October 2026.