Do contracts automatically renew?

Many contracts renew automatically, yes, if they contain an auto-renewal ('evergreen') clause, which is standard in SaaS subscriptions, service agreements, leases and insurance. The clause typically renews the contract for another term unless either party gives notice within a window before the renewal date, and that notice window is the trap. A '90-day notice' clause on a contract renewing January 1st means your real deadline is October 3rd, not December 31st.

Whether auto-renewal is enforceable varies by jurisdiction and contract type; consumer protections are stronger than B2B, where courts largely hold companies to what they signed.

The operational answer: read every contract for renewal language when you sign it, and record two dates: the renewal date and the notice deadline. It's the notice deadline that needs the reminder.