Usually to unlock a domain and transfer it, from what I have seen, you are required to buy one years renewal from the current registrar -- then the domain can be transfered to a new registrar. The registration does advance into the next year at the new registrar. So, you do get the renewal credit at the REGISTRY the lessor of that name to you -- the leasee. Or, beneficial rights owner.
To 'terminate' you just do not pay and the name eventually may go back to the registry.
https://www.hover.com/blog/what-happ...r-they-expire/