I have some questions about Adverse Action Notices. It is my understanding that for applications with joint applicants, we must specify to whom each denial reason applies. So for example: Applicant – Length of Employment, Co-Applicant – Limited Credit Experience, etc. Is it okay for all the reasons to be on each letter? That the applicant can see the reasons for denial that belong to the co-applicant and visa versa? Or can the applicant’s letter only have their specific reasons for denial?

No it's a privacy issue. You need to specify each of the applicants denial reasons to them separately and mail them separately as well.

And just where is the regulatory support for that statement?

You might want to pull put the 2003 preamble to the 2003 Regulation B amendments:

Section 202.9(b)(2), adopted as proposed, clarifies that whether a creditor’s denial of credit is based on the creditworthiness of the applicant, a joint applicant, or guarantor, the reasons for adverse action must be specific. For example, a general statement that “the guarantor did not meet the creditor’s standards of creditworthiness” is insufficient.

The legislative history of the requirement to provide specific reasons for adverse action indicates that the purposes of the disclosure are to help achieve the antidiscrimination goals of the ECOA and to educate and inform consumers. These dual purposes are served by the clarification in § 202.9(b)(2). For example, the disclosure may discourage a creditor from discriminating based on a co-applicant’s or guarantor’s race, sex, age, or other prohibited basis. Also, the disclosure may help educate and inform applicants, co-applicants, or guarantors as to reasons for denial that are not apparent from looking at their credit report.

Many commenters were concerned about the co-applicant’s or guarantor’s privacy when the reasons for adverse action pertaining to creditworthiness are given to the primary applicant. When a person agrees to be a co-applicant, guarantor, or similar party, however, there is (or should be) a general understanding that information will be shared. Accordingly, the rule has been adopted as proposed.

That addresses the Regulation B notice requirement, which should go to the primary applicant. The FCRA requirement, however, is that each applicant gets a separate FCRA notice if his or her credit report included information leading to the adverse decision.

I posted an ancillary question in the Lending Compliance forum: ECOA/Regulation B and Privacy

Please advise.