How do you use ChatGPT for due diligence?
Give the assistant the documents, ask it to quote them, and check every figure. In FinanceBench, GPT-4-Turbo answered 85% of filing questions correctly when pointed to the right passage, against 79% when it read nearly a whole filing and far less from memory (Fortune, December 2023).
What do general AI assistants do well in due diligence?
They read fast. ChatGPT, Claude and similar assistants summarise a 10-K, pull risk factors into a table, compare 2 years of MD&A, draft a list of questions for management and turn notes into a memo. Plans with file upload cost a reported $20 a month (Price Per Token, 2026). Used on documents you supply, they save hours of first-pass reading.
What do they do badly?
They recall facts poorly and present guesses with confidence. Without the source in front of them, models give revenue from the wrong year, confuse entities with similar names, invent subsidiaries or investors and cite pages that do not hold the claim. In the closed-book FinanceBench test, GPT-4-Turbo answered only 14 of 150 questions correctly (Fortune, December 2023). They also have no access to private data rooms, paid databases or registers unless you connect or upload them.
Step 1. Collect the primary documents first
Download the sources before you open the assistant. For a US public company, take the latest 10-K, the last 2 10-Qs and the 8-Ks from the past 12 months from SEC EDGAR. For a private company, take its Form D filings, its Companies House accounts if it is British, and any court dockets. The private company due diligence checklist lists what to gather.
Step 2. Upload the documents and fix the scope
Upload the files and tell the assistant to answer only from them. A prompt that works: "Answer only from the attached documents. If the documents do not contain the answer, say so. Do not use outside knowledge." This closes off most invented facts.
Step 3. Ask for quotes with locations
Ask for the exact sentence and its location for every figure: "For each number, quote the sentence and give the document name, item and page." A quote you can find with your browser's search is quick to verify. A figure without a quote is a figure to recheck.
Step 4. Use it for structure, not for verdicts
Ask it to build tables and lists: segment revenue by year, every related-party transaction, every legal proceeding, every change in auditor or officer. Keep judgement calls, such as whether a risk is material or a valuation is fair, with the analyst. The assistant can list the evidence; the decision rests on reading it.
Step 5. Check every figure against the source
Open each quoted location and confirm the number, the unit and the period. Follow how to fact-check an AI answer about a company for the full method. Note in the memo which figures you checked and when.
Step 6. Keep confidential material out of consumer accounts
Data room documents are often under a non-disclosure agreement. Check your firm's policy and the assistant's data terms before you upload them, and prefer an enterprise account with training on your data turned off. Public filings carry no such limit.
Where does Tamarly Intelligence help?
Tamarly Intelligence is Tamarly's research platform on companies, funds, countries and markets, built from official filings and open data. Every figure links to the filing or record it came from, which gives step 1 a starting point, and on Level 2 and above a reader can have Tamarly research a company from their portfolio and build a sourced profile of it. Ask the Brain answers with a numbered, graded source on every sentence and says plainly when a subject is not covered. Tamarly has no expert-call transcripts and no investor names on private rounds.
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Frequently asked questions
Can ChatGPT do due diligence on its own?
No. It can read and organise documents you give it, but it cannot confirm facts it was not shown, and it has no access to registers or data rooms unless you provide them. A person must check each figure against its source.
What is a good ChatGPT prompt for due diligence?
"Answer only from the attached documents. Quote the sentence and give the document, item and page for every figure. If the answer is not in the documents, say so." Then ask specific questions, one topic at a time.
Can ChatGPT read SEC filings?
Yes, when you upload the filing or the assistant can open it. Accuracy rises sharply when it reads the right passage: GPT-4-Turbo answered 85% of FinanceBench questions correctly when given the exact text (Fortune, December 2023).
About the author. Melvine Manchau is the founder of Tamarly and author of the Tamarly Newsletter. He previously worked at PwC, Salesforce, BlackRock/eFront and Lazard.
About Tamarly Research. Tamarly Research is part of Tamarly Media, which holds no investment positions. Tamarly is a New York research house that studies how AI is changing regulated institutions.