Is it common to do PPA without prior art search?

Your attorney was correct. However in my experience trying to attract financial investors without an issued patent is a waste of time. You don't have or own anything. The PPA just lets them know you have established a filing date for the eventual application your invention. How do you think showing a PPA will convince anyone that you will indeed have a patent with an existing claim that will be strong enough to cover you invention. Investors don't invest money on vapor. They want to see that they have protection before they put up their money. I would say if you believe in what you have go ahead an file a full utility application. A patent search does not even look at the patents filed within the last 18 months. What type of insurance is that to an investor that you will even get a patent issued on your invention?

Generally, we always prefer a patentability study prior to any patent filing unless the client is so knowledgeable in the field that they really know the prior art in the space. The study allows us to craft the application, assuming there's a reason to file at all, to anticipate objections which makes the patenting process far more efficient. With respect to provisional filings, we generally don't recommend those filings unless the circumstances truly warrant it. But for investors, they all will want to hear about competitors in the marketplace. The more sophisticated ones will want to know the IP competitive landscape as well. Given the relative low price for the study, the value to both patent strategy and potential investments would dictate doing it.

The answer to your question depends on the specific facts. I think it can make sense to file without a search (I think 1-2K is a little high for a search) such as when you have already disclosed or there is a absolute need for speed in the filing, but in general a search is a good idea whether for a provisional or a utility application. It can keep you from spending money on an invention that will be difficult to get a patent on and it can help strengthen the patent application. As to credibility of the application, it can be an issue to some investors, but certainly it is not fair to say that without a search the application has no credibility.

A prior art search is not required for the PPA which is primarily a "place holder" for a year to give the inventor time to finish the product, locate funding, and start production. Depending on what it is that you have invented, investors may be comfortable with the PPA without a search. You can do an informal search yourself on the USPTO web site if you are familiar with the search process. If you really believe that investors won't bite without confirmation of no prior art, you'll have to have one search done now and probably a second seach immediately prior to the formal application.

Best practice is to do a search first, but I've had plenty of clients do a provisional patent application before doing a search. Experienced investors will want to know that you are planning to do a search or that you had one done. They may defer an investment decision until after the search is completed.

A search is not required by the Patent Office - either for a provisional patent application (PPA) or for a formal utility application. A search does assist you in determining what you can claim as your invention, and thus can boost the credibility of the invention. However, no search is ever 100% perfect - and a patent examiner can sometimes find prior art that a search service failed to locate. Investors need to conduct their own due diligence regarding your invention - which is best protected by having an application on file before making any disclosure.

I would agree that if you are going to investors without a prior art search, you will have less credibility. In fact, investors might be more interested in the prior art search in comparison to the provisional application.