^^
(I'm the "all of the above" PP)
I meant to add, from the OP, technically speaking, that "personal" information isn't always so simple or easy. "Name" and "Address", not to mention any identifiers, are complicated. How many "names" do you allow? First, Middle, and Last is no longer a standard; there can be as few as two and certainly more than three. And what order do you display and/or verify them? Family name first or last? For reporting purposes, do you sort by the first surname? Are hyphenated names listed before or after two same names without a hyphen? Do you need to track "prior" versions? Or just keep "the current one"?
"Address," too, is all over the place with different constructs for street name parsing and delivery address can be different from location address (that's likely not a factor here). You'd think the USPS's database would provide some assistance but let's involve another big federal agency. /s
As for the "identifiers," they are the touchiest of components and often need security protocols. There is an
IRS standard for Federal Identification numbers but, given the current climate of -- well, we can't really require one -- it presents a potential legal or social quandary on how to validate input or advise of inaccuracies. What do you do if someone else has already used/reported that identifier? Do you just kick it out, allow it, flag the prior instance for audit/research?
So, what sounds so easy....isn't. And I haven't even begun to contemplate the intricacies of interfacing with IRS data. Can these all be spec-ed out? Sure. It just takes time and diligence and agility to adjust when yet another wrinkle arises.