Registries may have different requirements regarding how to change the registrant of a domain.
For some domains, a trade is necessary, but a trade does not always have a cost.
Some trades cause a change in the domain registration period, which always has a cost.
To check if there is a trade cost, you can check your account costs and see if there is a number listed in the "Trade" column.
Click here to access your account costs in the Control Panel.
For nTLD and gTLDs, the only extension that has a cost is .TRAVEL.
For ccTLDs, this can vary.