Keep every sub on your jobs covered
Small GCs and remodelers get billed when a sub had no valid insurance during the policy year. Sub Certs shows who is covered before that audit lands.
The premium-audit story
Your insurer assumes every sub on site was insured. If a certificate expired in March and you didn't notice until November, that payroll can be charged back to you.
Sub Certs chases renewals 30, 15 and 7 days before a policy ends, and flags expired coverage the morning it happens.
Sample requirement: standard subcontractor
General liability of at least $1M per occurrence and $2M total, auto $1M combined single limit, workers' comp with $500K employer's liability, plus additional insured, waiver of subrogation, and primary and non-contributory wording.
High-risk trades (roofing, framing, electrical) start from a tighter preset. You can change any limit.