Why is BIA collecting this information from me?
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
(a) As part of doing business with you, we must collect enough information from you to properly bill and service your account.
(b) We are required to collect your taxpayer identifying number under the authority of, and as prescribed in, the Debt Collection Improvement Act of 1996, Public Law 104-134 (110 Stat. 1321-364).
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.