I filed a Provisional Patent years ago and let it expire because there was no business opportunity at the time. Is it possible to refile as a new Provisional Patent with a new filing date?
Yes, with caveats.* You could also file a non-provisional application. What you have lost is the benefit of that earlier filing date. So any prior art or publications that have happened between the two filing dates can be used by the Patent Office to prevent you from getting a patent.
There may be other reasons you can’t get a patent on the invention anymore though. A big one is if there has been any public disclosure of the invention more than a year before the filing date.
*Note, I am not your lawyer
Thanks, Folly. It is what I hoped was the case.