How to switch from F4 to F3 category for family based green card

[drsingh]

I am a US Citizen and I filed I130 for my brother (and his wife, 1 son as derivative beneficiary) in 2007. Priority date is 10/5/2007, WAC08004xxxxx. This is in the F4 category, and after 13 years of waiting, another 3 years of wait is remaining in the queue.

In the meantime, our father has become a naturalized US citizen; so I think now my brother (+ his wife and 1 son) would qualify under F3.

1. What's the process to switch from F4 to F3 category? Does a new I130 need to be filed? If so, how do we retain the 2007 priority date?

2. F3 category priority date is June, 2008, so it would be immediately current. Right?

3. My brother is in India. Should he go for CP (requires visit to Bombay, as they only do immigrant visa processing in only 1 place), or should he try AOS?
(They all 10 year validity B1/B2 visa issued in 2015, and they have visited US twice in the past. The visa is still valid for all, and no overstays in the past).

4. My father has no income, but my income is plenty to be a cosponsor. Any other caveats?

Thanks for any inputs.

[newacct]

There is no "switch" or transferring priority dates between petitioners. A new petitioner (your father) needs to file a new I-130 petition, and the new petition's priority date would be right now, when the petition is filed. So it would be much slower than your petition for which visa numbers will become available in about 3 years.

[drsingh]

There is no "switch" or transferring priority dates between petitioners. A new petitioner (your father) needs to file a new I-130 petition, and the new petition's priority date would be right now, when the petition is filed. So it would be much slower than your petition for which visa numbers will become available in about 3 years.

Thank you for the response ... it would be great if you can provide some references where I can verify the above.

I am asking as I have seen many posts about people switching categories.