Preposition Usage

[nyoung2008]

Hi, I'm a bit confused with using the preposition word, "after" in the correct tense. For example, considering the following sentences:

1.)Are we required to do anything after we signed the contract?
2.)Are we required to do anything after we have signed the contract?
3.)Are we required to do anything after signing the contract?

Are the sentences above grammatically correct? The context is that the seller is trying to ask the lawyer whether he/she needs to do anything after signing the contract. The seller HAS NOT signed the contract yet.

Thanks.

 

[Horsa]

In British English 2 and 3 are correct, but 1 is not.

 

[nyoung2008]

What is the difference between 2 and 3?

Based on the context described above, which one (2 or 3) is more correct?

Thanks.