IP red flags when buying a company

The paperwork checks

A complete chain of title from every inventor to the current owner, in writing and recorded. Renewals paid across the whole family, verified from the register rather than from the seller's schedule. Working statements filed - since 2024 the statement is furnished once every three financial years and non-compliance carries penalties. And every licence, including informal or expired arrangements, because an exclusive licence changes what is being bought.

The substantive check nobody does

Read the independent claims yourself and write, for each key patent, the cheapest change a competitor could make to fall outside claim 1.

If that change is easy, the patent is decorative regardless of how many countries it covers. Count and certificates tell you almost nothing; claim 1 tells you almost everything.

Also check whether any pending case still discloses unclaimed subject matter that could support a divisional. That option closes at grant, and it is sometimes worth more than the granted claims.

What to actually do

• Verify renewals from the register, not the seller schedule.
• Trace every link in the chain of title and confirm recordal.
• Read claim 1 of each key patent and test how easily it is avoided.
• Identify divisional options before grant closes them.