When this guide is useful
A client needs historical payroll changes and several professionals are involved.
The distinction that matters
Identify who investigates, authorizes, files and verifies each correction. A tax adviser recommendation does not mean the payroll provider has implemented it.
A worked situation to investigate
An owner changes payroll firms after learning that a prior W-2 omitted an owner health insurance reporting item.
The example is illustrative. Begin with the underlying event and its source documents, then separate missing facts from disagreements about their treatment. Work through the checks below in the order that matches your file, rather than treating a completed checklist as a tax conclusion.
Build a traceable handoff
Identify the affected person, entity or property and the relevant period. Keep original evidence, corrections and the reviewer's written conclusion connected. If the facts change after review, preserve the earlier version and ask whether the change affects implementation.