CSV or XLSX for a generated data deliverable?

Choose the format from the next person’s task. A simple row exchange and a workbook with formulas have different needs, so do not ask for XLSX merely because it looks more polished.

Compare the practical differences

Decision	CSV	XLSX
Best fit	Portable flat records for another system	Multiple sheets, formulas and formatted review
Useful property	Simple to inspect and compare	Can keep raw and derived views together
What to check	Does not preserve multiple sheets or workbook formatting	Needs spreadsheet tooling and calculation review

A concrete choice

A cleaned import table may be best as CSV with a rejected-row companion. A review pack with formulas and explanations may benefit from XLSX.

Verify the choice

Open the result in the intended consuming tool and check dates, identifiers and leading zeroes before accepting it.

Write the reason for your choice into the task brief or setup notes. Then run a small representative task and compare the actual result with the requirement that drove the decision. Keep any unmet requirement visible rather than declaring the whole workflow ready from a single successful step.

Continue with the setup

The related desktop guide explains the relevant controls and limits. Use the current application state when applying this comparison; the presence of an option in a document does not mean every dependency on your computer is ready.