W-2 / 941 Year-End Reconciliation

The problem this kills

Every January, payroll managers and controllers face the same dread: the four quarterly 941s you already filed have to tie out, to the penny, against the W-2 totals on the W-3 you're about to send to the SSA. When they don't match, the IRS notices come months later, and untangling which quarter drifted is a forensic exercise in stale spreadsheets.

The usual fix is a hand-built reconciliation tab that one person guards, with formulas nobody else trusts, no record of who checked what, and no real gate stopping someone from filing while a line is still off. Known reconciling items - third-party sick pay, group-term life, retirement adjustments - get carried in someone's head instead of written down. One copy-paste slip and you're explaining a variance to the IRS.

This plan kills that. You get a real internal tool that does the arithmetic the same way every time, shows exactly which line doesn't tie, forces a human to investigate and approve before anything is called "filed," and keeps a permanent record of who signed off.

What you'll build

A small, private web app - just for your payroll team - that:

• Imports your four quarterly 941 totals and your aggregated W-2 / W-3 totals (from CSV or a Google Sheet).
• Sums the four quarters into annual 941 figures and compares them line-by-line to the W-2/W-3: total wages, federal income tax withheld, Social Security wages and tax, Medicare wages and tax.
• Applies your known reconciling items (third-party sick pay, group-term life, retirement adjustments) so expected differences don't show up as errors.
• Tolerates sub-penny rounding with a threshold you set, and flags everything above it as a real mismatch.
• Produces a mismatch list where the manager records the cause of each variance, then a clean reconciliation worksheet and tie-out report for sign-off.
• Won't let a tax year be marked filed until a manager has reviewed every mismatch and approved.

What's inside the Implementation Plan

• A discovery interview that runs first. Before it builds anything, the tool interviews you about how your payroll actually works - your provider, how your 941 and W-2 totals come out, your naming conventions, your typical reconciling items, and your filing deadlines - then reflects a short spec back for your thumbs-up. You get a tool tailored to your business, not a generic template.
• Copy-paste prompts for every build step, in order, written for a non-coder.
• A data model shaped around the exact 941 and W-2 lines you reconcile.
• The full comparison engine: annual roll-up, line-by-line tie-out, rounding tolerance, and reconciling-item handling.
• The mismatch investigation queue and the manager approval gate.
• The reconciliation worksheet and tie-out report, ready to print or save for the file.
• A no-integration fallback that works entirely off your 941 + W-2 CSVs and exports the finished worksheet.

The governance it includes (this is the point)

• Login so only your payroll team can open the tool.
• Row-level security so each organization only ever sees its own tax years and figures.
• A complete audit trail - who imported, who investigated, who approved, and exactly when.
• A hard human-in-the-loop approval gate: the tool computes and flags, but a payroll manager must review every mismatch and approve the reconciliation before a tax year can be finalized for filing.
• Duplicate guards keyed on the tax year, so the same year can't be imported and reconciled twice.

Who it's for

Payroll managers and controllers who must reconcile quarterly 941 filings to annual W-2s before year-end filing - especially anyone who today does it in a fragile spreadsheet and wants a repeatable, auditable, sign-off-protected process instead.

You've got this. Paste the first prompt and let the agent interview you.