When this guide is useful
A buyer receives a broad promise to reduce taxes but no list of completed work products.
The distinction that matters
Compare the written deliverables and excluded work before comparing headline fees. Advice, preparation and implementation can be separate engagements.
A worked situation to investigate
One quote includes an annual planning meeting while another includes documented recommendations and quarterly follow-up.
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.