TinKindUS

Which kind of US taxpayer identification number a value turned out to be.

A field labelled just "Tax ID" can hold three different kinds of nine-digit number: an SSN (a Social Security number — a person), an ITIN (an Individual Taxpayer Identification Number — a person who cannot get an SSN), or an EIN (an Employer Identification Number — a business). The label alone does not say which. CkUS.Tin reads the value's shape and answers with a TinKindUS, so you can route the value to the right validator, column or mask.

Members

Member	Meaning
Invalid	Not a structurally valid SSN, ITIN or EIN — a missing value included. This is the fallback answer.
Ssn	A Social Security number; the shape CkUS.Ssn accepts.
Itin	An Individual Taxpayer Identification Number; the shape CkUS.Itin accepts.
Ein	An Employer Identification Number; the shape CkUS.Ein accepts.

Where it is used

Only CkUS uses it: Tin returns a TinKindUS. It tries Itin first, then Ssn, then Ein, and answers Invalid when none of them accepts the value — or, with throwIfInvalid: true, throws a CkUSException that says why. One caution from its docs: a bare nine-digit value that is structurally a valid SSN is reported as an SSN even when it would also pass as an EIN — only the dashed "12-3456789" layout is unambiguously an EIN. And it classifies shape only; it does not tell whether the number was ever issued.

Quick look

using SafeCoder.CommonKit;
using SafeCoder.CommonKit.Enums;

CkUS.Tin("912-70-1234");    // -> TinKindUS.Itin     (the area starts with 9)
CkUS.Tin("12-3456789");     // -> TinKindUS.Ein      (the dashed 2+7 layout)
CkUS.Tin("123456789");      // -> TinKindUS.Ssn      (bare nine digits read as an SSN)
CkUS.Tin("12345");          // -> TinKindUS.Invalid  (too short for any of the three)