Numbers you can plan around.
Before any record moves, the definition of the audience is agreed. Names and addresses are folded consistently so comparisons mean something. What arrives is a file whose every column has a written definition.
Consent position
Stating what basis exists for contacting each segment, and where that basis is absent.
Re-supply terms
Agreeing in advance what happens if the file turns out to be wrong.
Suppression handling
Applying exclusion lists before counting, so the approved figure and the delivered figure are the same number.
The counts cost nothing. What they imply is the part worth discussing.