You can give nicknames to your Pokémon in Sword and Shield, but if you decide you don’t like one, then you are in luck: Nicknames are not permanent, and they can be changed. The only time you cannot change a nickname is if you get the Pokémon through a trade. If you are trading for a Pokémon and want it to have a different nickname, ask the person you are trading with to do it before the trade is made.
How to Change a Pokémon’s Nickname in Sword And Shield
To change a Pokémon’s nickname, go to any Pokémon Center. When you go inside, you will notice a counter to the left side of the room. Walk up to the counter and hit A. The man behind the counter will give you some options. You can rate a nickname, remember a move, and forget a move.
Select rate a nickname, then pick the Pokémon whose nickname you wish to change from the screen. The man will give his verdict on the nickname, usually by telling you it is quite a fine nickname, but he will also say you can give it something better. Hit “Yes,” then enter the new nickname you wish to use for that Pokémon.
You can do this as many times as you like, for as many Pokémon as you want, for no cost in-game. Just keep in mind, nicknames cannot be changed after trades, so if you do trade Pokémon, make sure everyone is happy with the nicknames before you finish the trade.