What should a private company due diligence checklist include?
A usable checklist covers 7 groups: identity and ownership, fundraising, financials, legal and credit, sanctions, intellectual property and people. Each item should name the record that answers it. In the UK, a charge must be registered within 21 days of its creation (GOV.UK), so the charges register is a fast credit check.
Who is this checklist for?
It is written for investors, corporate development teams, lenders and advisers doing a first pass before management access or a data room. Practitioner guides agree on the core idea: test management's claims against evidence you can verify independently (Beauhurst). Private companies add their own risks, such as dependence on the owner, minority shareholder rights, unaudited financials and informal governance (Dealroom).
The questions people search most are practical: what goes on the list, which checks can I do for free, and what are the red flags. The checklist below answers those with public records. A full legal and financial diligence in a transaction goes further, through the data room and advisers.
What are the 7 groups to check?
| Group | Question | Free record to check | Red flag |
|---|---|---|---|
| 1. Identity | Is the legal entity what the company says it is? | State registry; UK Companies House; GLEIF LEI record | Brand and legal name do not match; recent change of name |
| 2. Ownership | Who controls the company? | UK register of people with significant control; Form D related persons | No identifiable controller; frequent changes |
| 3. Fundraising | What has it raised and when? | SEC EDGAR Form D history | Claimed raise with no filing and no announcement |
| 4. Financials | Is there evidence of revenue and solvency? | UK filed accounts; Form D revenue band | Overdue accounts; negative net assets |
| 5. Legal and credit | Is it in disputes or heavily secured? | CourtListener RECAP; UCC filings; UK charges register | Recent cluster of suits or liens |
| 6. Sanctions | Is it or its owners on a list? | OFAC Sanctions List Search; UK, EU and UN lists | Name match on an owner or director |
| 7. Intellectual property | Does it own what it says it owns? | USPTO Patent Public Search | Patents assigned to a founder or another entity |
A final group sits outside the table: people and commercial claims. Check executive backgrounds, named customers and hiring trends, as set out in our guide on how to research a private company.
How do you check identity and ownership?
Confirm the exact legal name, entity type, jurisdiction and registration number before anything else, because every other search depends on it. In the UK, the register of people with significant control lists anyone who holds more than 25% of the shares or voting rights, directly or indirectly (GOV.UK). Since 18 November 2025, new directors and people with significant control must verify their identity with Companies House (CMS). In the US there is no public owner register for most private companies, so ownership work starts from Form D related persons, state filings and announcements. Our guide on finding who owns a company covers the method.
How do you check fundraising history?
Search the company on SEC EDGAR for Form D notices. A Form D must be filed within 15 days after the first sale in the offering (17 CFR 230.503), and it shows the amount sold, the exemption and the number of investors. A missing Form D is not proof that no raise happened: a Lehigh study of almost 40,000 venture rounds found that more than 50% had no Form D on file (Hanley and Yu, ECGI). Ask the company to explain any gap.
How do you check financials without a data room?
For UK companies, download the filed accounts from the Companies House filing history and compare at least 3 years. Private limited companies must file accounts 9 months after the financial year ends (GOV.UK), so an overdue filing is itself a signal. For US companies, public financials are rare. Use the Form D revenue band if one is given, and build an estimate using our guide on estimating private company revenue.
How do you check litigation, liens and charges?
Search federal dockets on CourtListener's RECAP Archive, which is free but only as complete as the PACER documents its users have contributed (Free Law Project wiki). State court records and UCC lien filings sit with each state. In the UK, the charges section of the Companies House record shows secured lenders. A charge not registered within 21 days needs a court order to register (GOV.UK), so lenders file promptly and the register is usually current.
How do you screen for sanctions?
Search the company, its directors and its owners on OFAC's Sanctions List Search and on the UK, EU and UN lists. The OFAC tool uses fuzzy matching with an adjustable confidence threshold, and OFAC states the tool does not replace appropriate due diligence (OFAC). Record each near match and why you cleared it.
How do you check patents?
Search the assignee name in USPTO Patent Public Search, the free tool that replaced the older PatFT and AppFT systems in 2022 (USPTO). Confirm that key patents are assigned to the company, not to a founder or a former employer.
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. Several groups of this checklist are built in. The law firms workflow screens clients against the US (OFAC), UK, EU and UN sanctions lists. Each company in the Venture workflow has its Form D history rebuilt into rounds and its US patents. Company pages draw on SEC EDGAR, UK Companies House, GLEIF and CourtListener, and every figure links to the filing or record it came from.
There are limits. Tamarly shows no investor names on private rounds, no expert-call transcripts and no data room documents, and when it does not cover a company it says so. On Level 2 and above you can have Tamarly research a company from your portfolio and build a sourced profile of it.
Run sanctions, filings and patents checks on a private company free for 7 days
Frequently asked questions
What are the main types of due diligence?
Guides usually split it into financial, legal and regulatory, and commercial diligence, with technology and people reviews added for larger deals (Beauhurst). The checklist above covers the parts you can start from public records.
Can I do due diligence on a private company for free?
You can do a solid first pass. Form D filings, UK Companies House records, CourtListener, USPTO and the official sanctions lists are all free to search. Detailed financials, contracts and cap tables need the company's cooperation.
What is the biggest red flag in private company due diligence?
A claim you cannot match to any record, such as a funding round with no Form D and no announcement, or a controller who appears on no register. One gap can have an innocent reason, so ask management, but several together call for a deeper review.
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.