Excel Sales Data Accuracy Validation

I have several spreadsheets of raw sales transactions pulled from different systems. Before the numbers feed our dashboards, I need one consolidated file whose figures I can trust. Your job is pure data cleaning and validation—no manual re-keying—focused entirely on verifying the accuracy of the sales data already in place.

Here is what I need from you:

• Examine every column (dates, order IDs, SKU codes, quantities, prices, tax, totals) and confirm each record is internally consistent.
• Recalculate extended prices and grand totals with formulas to catch calculation errors or missed tax.
• Cross-check SKU codes against the master product list I will supply; flag any that don’t match.
• Identify and clearly mark blank or suspicious values that require my review rather than guessing.
• Apply Excel data-validation rules and conditional formatting so future uploads trigger immediate warnings.
• Provide the final, validated workbook plus a short change log explaining what was fixed, what was flagged, and any trends you noticed.

I work in Microsoft 365, so feel free to lean on dynamic arrays, XLOOKUP, Power Query, or whatever advanced Excel tools speed the process—as long as the final file opens cleanly in standard Excel.

Acceptance criteria: every flagged inaccuracy is either corrected with traceable logic or listed in the change log; summary totals in your file match the underlying line-item math; no broken formulas or hidden errors remain.

If you’ve done rigorous sales-data validation before, especially using Power Query or VBA for quality checks, you’ll breeze through this. Let me know your typical turnaround time and any clarifying questions.