A provisional application is a priority-date placeholder: it is never examined, never publishes on its own, and expires in 12 months. Done right, it locks in your filing date for a fraction of the cost of a full application. Done as a cheap formality, it can be worse than nothing – because a provisional only protects what it actually describes.
What a good provisional contains
The one-year-later non-provisional can only claim priority to what the provisional discloses. That means a good provisional is not a napkin sketch and an abstract – it's a real technical description: how the invention works, the alternatives and variations you might later claim, and enough detail that a person in your field could build it.
- Full technical description of the invention and its variations
- Informal drawings are fine; missing embodiments are not
- Drafted with the eventual claim set already in mind
- Filed before any public disclosure, pitch, or offer for sale where possible
When a provisional is the right move
You're still iterating on the design. You're about to demo publicly or pitch investors. You need "patent pending" status on a startup budget. You want 12 months of market signal before committing to full prosecution costs. All of these are exactly what provisionals are for.
The 12-month decision
Before the provisional expires you either file the non-provisional (claiming the provisional's date), refile if nothing has been disclosed, or let it lapse. We calendar that deadline with you from day one and use the year to sharpen the claim strategy – not to forget about it.
Where provisionals go wrong: thin disclosures that don't support the later claims, and blown 12-month deadlines. Both are drafting-and-process problems, and both are preventable.