Expiry is not a cliff, but it is a slope, and the exact timing varies by registry and registrar. A typical .com goes through these stages.
On the expiry date, the domain is usually switched off or pointed to a parking page. For a period of up to about 30 to 45 days, depending on the registrar, you can renew at the normal price. After that comes a redemption period of around 30 days, in which recovery is possible but costs significantly more. Then a short pending-delete stage of about five days, and finally the name is released for anyone to register.
Your website and email go offline at the first step, not the last. Renew early, and do not treat the grace period as a plan.
The timeline in one picture
Day zero is the expiry date written in the registration record, not the day the renewal reminder arrives. The figure uses typical .com figures; check your own registrar's terms, because some shorten the first stage and some sell the name on to an auction partner before it is released.
Stage one: the renewal grace period
This is the stage in which most owners rescue the name, and the one that varies most. For generic endings the registry allows up to 45 days of auto-renew grace, and many registrars offer 30 or less. During it you renew at the ordinary price, and the name continues as if you had never missed the date.
What changes at once is the service. Many registrars point the domain at a parking page with advertising, which means your nameservers are replaced and your site and mail stop working. Visitors may see ads under your name. Some registrars leave the DNS alone for a few days, which is a bonus you should not count on.
Registrars are required to send reminders around a month and a week before expiry, and again shortly after. They go to the registrant email, which is why an unmonitored contact address is the usual cause of an accident.
Stage two: redemption
If the grace period passes, the registry puts the name into a redemption period of around 30 days. The domain no longer resolves at all. You can still recover it, but your registrar has to ask the registry to restore it, and the restore fee is usually a significant multiple of the normal renewal. On top of that, the registrar's own handling fee applies. Some registrars do not offer recovery here, or only through support, so do not rely on a web button.
Stage three: pending delete, then release
Once redemption ends, the name enters pending delete for about five days. Nobody can renew it now, not even the previous owner for money. At the end of that period it drops out of the registry and becomes available to anyone.
The moment of release is predictable, and a number of businesses watch for valuable names and try to register them the second they drop. If your domain had traffic, backlinks or a recognisable name, assume someone is waiting. Once registered by another party, getting it back is a negotiation or, if you have a trademark claim, a formal dispute.
Names on country-code endings often run to different schedules, some without any redemption period. Read the registry's terms.
Protecting yourself in practice
The simplest defence is dull and works: renew a month or more ahead, for several years if the registrar allows, and put the date in two calendars. Keep the contact address on a different domain, read the reminders and treat a failed payment email as urgent. Everything after the expiry date costs more or removes options.
Checking it yourself
whois example.com | grep -iE "expir|status"
Registry Expiry Date: 2027-03-14T12:00:00Z
Domain Status: clientTransferProhibitedStatuses to know: autoRenewPeriod means you are in grace; redemptionPeriod means pay the restore fee; pendingDelete means it is too late. The SSL expiry checker covers certificates, which follow their own dates, and it is worth diarising both.