What is the difference between claiming foreign priority and claiming benefit of a U.S. provisional application?

Claiming foreign priority under 35 U.S.C. 119(a)-(d) and claiming benefit of a U.S. provisional application under 35 U.S.C. 119(e) are similar in some ways but have important differences:

1. Time limit:
– Foreign priority: Must be claimed within 12 months (6 months for design applications)
– Provisional: Must be claimed within 12 months

2. Effective filing date:
– Both can provide an earlier effective filing date for prior art purposes

3. Patent term:
– Foreign priority: Does not affect patent term
– Provisional: The 12-month period counts towards the 20-year patent term

4. Disclosure requirements:
– Both require the earlier application to provide adequate support for the claimed invention

5. Formalities:
– Foreign priority: Requires a certified copy of the foreign application
– Provisional: No certified copy required, but the provisional must be in English

6. Inventorship:
– Foreign priority: Requires at least one common inventor
– Provisional: Requires at least one common inventor

7. International effect:
– Foreign priority: Recognized in other Paris Convention countries
– Provisional: May not be recognized in some foreign jurisdictions

Both types of priority claims can be valuable for establishing an earlier effective filing date, but they have different requirements and effects that should be considered when developing a patent strategy.