Is there a provisional PCT application?

No, there is no provisional PCT application, and provisional applications, just like non-provisional applications, are territorial - meaning, they are only valid within the country that it was filed in. Of course, the provisional app can then serve as the basis for a PCT app which then opens the door to other countries.

There isn't a provisional patent application under the PCT. One of the main advantages of a provisional patent application is that it secures a priority date for your patent application and provides you 12 months to decide on the countries that you want to obtain patent protection. Individual patent applications filed in the countries of interest before expiry of this 12 month period are granted a priority date that is backdated to the filing date of your provisional patent application. This is important during examination of your application. Alternatively, if you need more time to decide, you can file a PCT application before expiry of the 12 month period. This will provide a further 18/19 months for you to decide on the countries of interest.

One strategy that you can consider is filing a PCT application at first instance, instead of a provisional patent application. An advantage of such a strategy is that you will be able to secure a priority date for your patent application and have 30/31 months to decide on the countries that you want to seek patent protection without incurring the cost of a provisional patent application. The downside to this approach is that a PCT application is considered a complete application and will be publicly available after about 18 months. A provisional application typically remains confidential if a complete application is not filed during the 12 month period.