Answer:
A tax preparer can disclose a taxpayer's information with another tax preparer that works in the same firm that he/she does, as long as they are both located in the US.
A tax preparer can disclose a taxpayer's information with another tax preparer that does not work in the same firm that he/she does, are both located in the US, and the purpose of the disclosure is to provide auxiliary services or assist in the preparation of a tax return of a another taxpayer.
