Certified payroll guide
The last-four Social Security number rule on the weekly transmittal
29 CFR 5.5(a)(3)(ii)(B) explains why the certified payroll carries only the last four digits, and why our preflight refuses a full nine-digit number.
The single most common way a certified payroll leaks personal data is also the one the regulation names outright. The weekly transmittal must not contain full Social Security numbers, and it does not need to.
What the rule says
29 CFR 5.5(a)(3)(ii)(B) requires the certified payroll submitted to set out the information the contractor must otherwise keep, but states that full Social Security numbers, last known addresses, telephone numbers and email addresses must not be included on weekly transmittals. Instead, the payroll needs only an individually identifying number for each worker - for example, the last four digits of the Social Security number.
Two different records
The rule turns on a distinction that is easy to miss. The contractor's own payroll records, under 29 CFR 5.5(a)(3)(i)(B), contain the worker's name, Social Security number, address, phone number and email. The transmittal sent to the agency, under the paragraph above, must not. Same worker, same week, two documents with different privacy rules.
Why our preflight refuses it
A nine-digit number submitted to a free preflight would end up in a marketing database holding construction workers' Social Security numbers. That is both a data-protection exposure and a compliance defect, because the document being validated is the one that is supposed to leave those numbers out. So our preflight treats any nine-digit number as a hard error, names the rule, rejects the submission and does not store the number. The correction is the last four digits.
Sources: U.S. Department of Labor, Wage and Hour Division — WH-347 certified payroll form and instructions; 29 CFR 5.5 (contract provisions and related matters). This guide is general information, not legal advice, and not a determination by any agency. Owned and operated by GCExperts LLC.