Use SIC codes as a first-pass filter
SIC codes give due diligence teams a practical starting point for narrowing a large market into a relevant, reviewable cohort of companies.
They are not enough on their own, but they help eliminate clearly irrelevant businesses before analysts begin deeper review.
Layer on risk and financial filters
When you combine SIC filters with status, financial thresholds, and location, you can move from broad market scans to a credible shortlist much faster.
That improves both research speed and auditability because your selection criteria are explicit rather than buried in ad hoc spreadsheet work.
Keep the rationale visible
Good due diligence is not just about arriving at a list. It is about being able to explain why that list exists, what rules produced it, and how it can be revisited later.