What if my w2 does not have anything in box 15

pcoffey2016 — Sat, 01 Jun 2019 06:53:35 GMT

You can use the federal ID number that is listed in box "...

LaurenB — Sat, 01 Jun 2019 06:53:37 GMT

You can use the federal ID number that is listed in box "b" if there is not state ID number listed on your W2 in box "15"

In some instances the state mailing abbreviation (that is, the 2 letters specific to your state e.g. FL, NY, CA etc.) also works.