Fintra Payroll
W-2 boxes that are right because the YTD is right
How W-2 boxes are built
W-2 errors almost always come from wages that were bucketed wrong during the year, not from year-end. Because Fintra tracks taxable wages per basis on every paycheck, year-end W-2 generation is a direct read of those accumulators: no reconstruction, no spreadsheet.
| Box | Source | Note |
|---|---|---|
| Box 1: wages | FIT-taxable wages YTD | Gross minus 401(k) deferrals minus Section-125 |
| Box 2: FIT withheld | FIT withheld YTD | |
| Box 3: SS wages | Social Security wages YTD | Already capped at the wage base by the engine |
| Box 4: SS tax | SS withheld YTD | |
| Box 5: Medicare wages | Medicare wages YTD | Gross minus S-125; 401(k) does NOT reduce Box 5 |
| Box 6: Medicare tax | Regular + Additional Medicare | |
| Box 12D / 12DD | 401(k) deferrals / health cost | Employee S-125 + employer-paid share |
| Box 16 / 17 | State wages / state withheld |
Built-in correctness checks
Relationships the tests assert
- Box 1 < Box 3 and Box 5 whenever a 401(k) deferral exists
- Box 5 < gross whenever a Section-125 deduction exists
- Box 12DD combines employee pre-tax health premiums and the employer-paid share
- Additional Medicare rolls into Box 6, not a separate line
What’s real and what’s a stub
Inside Fintra
Employees can check their my-w2-status from the portal, and the w2-summary report gives payroll admins every box for every employee for the year in one view.
Questions people ask
Why do Box 1, Box 3, and Box 5 differ?
401(k) elective deferrals reduce Box 1 (and are FIT-deferred) but are still Social Security and Medicare wages, so they don’t reduce Box 3 or Box 5. Section-125 pre-tax health reduces all three. Fintra tracks each basis separately all year so the boxes fall out correctly.
Does Fintra file W-2s with the SSA?
Fintra computes and reports every W-2 box today. The official PDF rendering and EFW2 e-file export are documented stubs still on the roadmap, so filing is handled outside Fintra for now.
What feeds Box 12DD?
The employer-sponsored health cost: the employee’s Section-125 pre-tax premiums plus the employer-paid share, both tracked on paychecks during the year.
Can employees see their W-2 data?
Yes: the employee portal exposes a my-w2-status view, and admins get a full w2-summary report across the org.
Keep reading
Guides
One finance briefing a week
New guides, checklists and benchmarks, by email. Unsubscribe from any issue.
W-2 season without the reconstruction
See how Fintra derives every W-2 box from year-round, per-basis wage tracking.