The columns you need
Vendor legal name, trade, contact email, project, GL each-occurrence limit, GL aggregate, GL expiry, auto CSL, auto expiry, WC employer's liability limit, WC expiry, umbrella limit, umbrella expiry, additional insured (Y/N), waiver of subrogation (Y/N), primary and non-contributory (Y/N), certificate holder correct (Y/N), date received, reviewed by, and a link to the PDF. Add a status column with a formula: expired if any expiry is before today, expiring if any is within 30 days, non-compliant if any limit is below your minimum or any endorsement is N, otherwise compliant.
Formulas that do the work
Next expiry: =MIN(GL expiry, auto expiry, WC expiry, umbrella expiry), ignoring blanks. Days remaining: =next expiry − TODAY(). Status: nest IFs from the harshest condition down, so an expired line always wins over a limit problem, and a limit problem always wins over “expiring”. Conditional formatting on the status column makes the sheet scannable in a weekly meeting.
Where the spreadsheet breaks
Data entry. Someone has to open every PDF and type fifteen fields. At 25 vendors on three policy cycles, that is a certificate a day and the typing errors become the risk.
Reminders. The sheet knows a policy is expiring but cannot email the sub. Someone has to look, then write the email, then follow up.
Multiple projects. The same sub on three jobs with different owners' requirements means three rows or three sheets, and the certificates drift out of sync.
Audit trail. When an insurer or attorney asks what you had on file the day of an incident, a spreadsheet has no history — only its current state.
When to move off the spreadsheet
A practical threshold is 20–30 active vendors or more than one concurrent project. Below that, a disciplined sheet works. Above it, the manual steps get skipped under schedule pressure, which is exactly when the exposure matters. Purpose-built tools like CoverClerk read the certificate for you, send the reminders, keep per-project requirements, and log every change — the same columns above, with the typing and chasing removed.