Isn't it a pull process? As in, you set up the transfer with the gaining registrar and I believe NIC.es email you and you have to approve it.
i did this many years ago and will need to do it again soon i think you initiate the transfer (change the tag) in your registrant account at dominoes i am not looking forward to the transfer it took me weeks last time to get it sorted
https://www.dominios.es/dominios/en start here last time the registered email was the registrar and took ages to get them to amend the domain with my details should be straight forward if you have access to the email account the registry have on file
Thanks a lot guys. The domain name is currently with EuroDNS, all they want me to do was start a transfer and ask the buyer to do the same from their end. I am supposed to receive email from NIC.es(like Ben said above), but the buyer does not have a registrar and have created account with NIC.es. I asked DAN .com to ask the buyer to create account with EuroDNS which should make it easier but they ask me to ask EuroDNS if they could transfer the domain name to the buyer's NIC handle and this is not EuroDNS process. Although I emailed them to find out if they can do this, still waiting for reply. Also, I found out that NIC.es can be your registrar too but at a higher cost, I guess similar to Nominet been your registrar. I have asked DAN to ask the buyer to initiate the transfer from NIC.es and I am waiting to hear back. Thanks again.
All done. The key to .es transfer is to have NIC handle with Nic.es. Seller start the transfer by placing the domain in a transfer state. Buyer's registrar initiate the transfer via Nic.es, Nic.es contact the admin of the domain via email asking him to accept or cancel the transfer. By accepting the transfer, it automatically completes the transfer. This was the only .es domain I had and now its with new owner. Thanks guys.