For instances where you have an application with a "TBD" address (not a construction - but a true TBD when an applicant is shopping for a home), then the applicant selects a home and provides an address, what application date should be used...the initial application date on the 1003 with the TBD address, or the application date on the 1003 that includes the full address?

Are you doing pre-qualifications?

We do not have a formal pre-approval program, but yes, we do pre-qualifications.

You don't have a true application until you identify a property.
What 6 Pieces of Information Make A TRID Loan Application?
Name.
Income.
Social Security Number.
Property Address.
Estimated Value of Property.
Mortgage Loan Amount sought.

So the application date cannot be the date you got info for the prequal.
If you have the other five items for the prequal, the date you get an address is the application date.

NOTE: You do NOT have to have the OTP to receive the address. If the borrower calls and says 'our offer on 123 Main got accepted' the clock starts for TRID.

TRID and HMDA application definitions aren't necessarily the same. Your own policies and procedures should clarify how you define and accept applications for Reg B/HMDA, but a pre-qual isn't an application under HMDA, so you don't generally have an app until you have an address.

1003.2(b)-1. Consistency with Regulation B. Bureau interpretations that appear in the official commentary to Regulation B (Equal Credit Opportunity Act, 12 CFR part 1002, Supplement I) are generally applicable to the definition of application under Regulation C. However, under Regulation C the definition of an application does not include prequalification requests.

2. Prequalification. A prequalification request is a request by a prospective loan applicant (other than a request for preapproval) for a preliminary determination on whether the prospective loan applicant would likely qualify for credit under an institution's standards, or for a determination on the amount of credit for which the prospective applicant would likely qualify. Some institutions evaluate prequalification requests through a procedure that is separate from the institution's normal loan application process; others use the same process. In either case, Regulation C does not require an institution to report prequalification requests on the loan/application register, even though these requests may constitute applications under Regulation B for purposes of adverse action notices.