Customer Data Spreadsheet Structuring

I have several raw spreadsheets full of customer information and I need them reorganised so they can power clear-cut customer demographics reports. The work involves standardising column headers, cleaning obvious entry errors, merging duplicates, and arranging all records so they flow into pivot tables or other summary views without extra tweaks.

My end goal is to open the file, refresh, and instantly see accurate snapshots of age groups, locations, purchase frequency and any other demographic slice that’s already present in the data. A well-structured master sheet plus one or two example reports or dashboards that prove the layout works will be the key deliverables.

Feel free to use Excel, Google Sheets or another mainstream spreadsheet tool—as long as the final file is shareable and continues to update correctly when new rows are appended. If formulas, Power Query or simple macros make the workflow cleaner, add them with comments so I can maintain them later.