I have just started the transfer of a domain to Cloudflare. The transfer will take 4 days and I can not speed up the process. However, the domain is going to expire and I need to renew it. How can I renew the domain? Should I renew it on the old provider or wait until the transfer is completed to renew it on Cloudflare?
So, the actual terms and procedures may vary, depending on which TLD you have.
During the transfer, most TLD will typically add a new year on top of the current expiration.
I wouldn’t do this, as it would just complicate things in other directions.
The renewal would typically be returned from the registry to previous provider, and you would therefore NOT get a new year on top of the current expiration with the transfer.
The double payment you may have ended up on making (e.g. 1 x transfer, 1 x renewal), you would then have to go through the process of escalating that with your old provider, in order to attempt to get the payment for the renewal refunded.
My suggestion would be , wait and follow up once the transfer has completed.