Blank Lookups are a design decision, not an accident waiting to happen. Decide whether a lookup is allowed to be blank; if it is not, enforce it; if it is, handle the blank case explicitly.
- Audit current lookup fields
For each lookup, decide whether blank is acceptable. Document the decision per field; the decision drives validation rules, formulas, and reporting.
- Mark genuinely required lookups as Required
On the field definition. The platform-level required flag is the cheapest enforcement.
- Add validation rules for conditional requirements
When a lookup is required only under certain conditions (Type = Customer), use a validation rule with ISBLANK to enforce it. The rule should explain the business reason in the error message.
- Null-guard formulas, Flows, and Apex
Any code or formula that references a lookup needs an ISBLANK or null check. Skipping the check produces silent wrong answers or runtime errors.
- Surface Blank Lookups in reporting
Build a report or list view that finds records with blank lookups in fields that should be populated. Run it weekly so the data quality issue gets visibility before it grows.
- Required-by-business-logic lookups left as Optional on the field definition leak blank values through the API. Apex inserts and data loads can bypass the UI requirement.
- Standard parent-child reports exclude blank-parent records. The implicit filter hides data quality issues from sales operations.
- Apex code that does not null-guard lookup traversal produces NullPointerExceptions when the lookup is blank.
- Sharing inherits through lookups. Blank lookups produce orphan records with no inherited sharing.