Check whether one table really points to records in another
Use Spreadsheet Relationship Check when one table contains primary identifiers and another table contains references that should point back to them. Typical examples include orders linked to customers, line items linked to products, participants linked to groups or files linked to records.
Find blank keys, duplicate primary IDs and missing references
A primary identifier should normally be unique when it defines one record. Duplicate IDs make relationships ambiguous, while a reference with no matching primary record indicates an unresolved link. The check surfaces these structural problems without changing the tables.
Identifiers are compared as identifiers
Values such as 00123 can carry meaning that would be lost if silently converted to numbers. TaskThimble avoids coercing identifiers when that could change the relationship being tested.
Relationship structure is not business correctness
A valid reference only shows that the referenced identifier exists. It does not prove that the underlying customer, product, invoice or other record is factually correct or should be linked in the business sense.
Fix the source relationship, then re-check
Resolve duplicate IDs, blank keys or missing referenced records in the appropriate source, then run the relationship check again before using those identifiers in matching or downstream workflows.