About the grace period
Every 2LD (second-level domain, like name.eth) will have a 90 day grace period after the name’s registration expires.
What restrictions are there during the grace period?
During the grace period the owner of the name, or an approved manager will not be able to update the ENS records. While in the grace period, the state of the name is "locked" so no changes can be done until it has a valid and current expiration in the future. For instance:
The name’s ownership cannot be transferred.
The ETH address cannot be updated or any other records for the name.
Listings and trades on secondary markets like Open Sea not work.
Extending names your wallet does not own
To get the ENS name out of grace period, the name’s registration must be extended. However, any wallet can extend a 2LD ENS name. This might be useful if the ownership of the ENS name is with a hardware wallet, and it’s easier to extend the name using a hot wallet instead of the hardware wallet.
Another common scenario is that maybe a friend forgot to renew their ENS name. Extending the registration for them from your own wallet is possible. Extending a name you don’t own does not give access or ownership of the ENS name to you.
Are there grace periods on ENS names that are not .eth?
Imported DNS names, like a .com for instance, do not have registration fees or renewals. Therefore, only 2LD ENS names have yearly costs. Some TLD operators like .art and .box use the underlying ENS protocol within their registrar, and those may have some type of registration fees depending how they have designed their registrar services.
Is the ENS name still functional while in grace period?
Yes, your name and records remain intact. Sending Ethereum tokens to the name will still arrive at the wallet address the name is pointed to. However, it’s not possible to update any of the records for the name stored on the ENS public resolver.
What happens when the grace period ends?
Once the grace period ends, the ENS name can no longer be renewed, only registered again. After the grace period ends, the name goes into a 21 day premium period starting very high ($100M and exponentially falling to $0 premium fee on 21st day). Once the ENS name exits out of the grace period and goes into the 21 day premium auction window, the ownership has been lost. The name will technically continue to function, as all records will remain for the name. However, if the name is registered again, all records are reset(the existing NFT token gets burned) and the ownership and basic records like the ETH address are automatically changed over to the new owner.