Answer:

SSN

Answer	Crossword Clue
SSN	Nine-digit ID
SSN	Worker's ID
SSN	123-45-6789?

SSN	I.D.,often
SSN	Common ID
SSN	W-2 info.
SSN	Access code, sometimes: Abbr.
SSN	Phishing string: Abbr.
SSN	9-digit ID
SSN	Nine-fig. ID
SSN	ID-theft target

SSN	ID info
SSN	ID on IRS forms
SSN	Blank on a job app.
SSN	Identity thief's need, for short
SSN	Amer. ID
SSN	Govt. ID
SSN	ID with two hyphens
SSN	Credit-report fig.

SSN	Form 1040 ID
SSN	String sought by those going phishing?: Abbr.
SSN	Govt.-issued ID
SSN	ID since 1936
SSN	Application no.
SSN	Payroll ID
SSN	USA ID
SSN	Application datum: Abbr.

SSN	IRS datum
SSN	Personal ID
SSN	Taxpayer ID
SSN	Form 1040 no.
SSN	IRS form datum
SSN	Tax form ID
SSN	Form 1040 info
SSN	Form 1040EZ info

SSN	IRS ID
SSN	Job app ID
SSN	Job app no.
SSN	W-2 datum: Abbr.
SSN	Box "d" on the IRS W-2