Does the Pokémon Sword Expansion Pass expire?

The Pokémon Sword Expansion Pass does not have an expiration date. Once purchased, players can access the additional content included in the Expansion Pass indefinitely. This includes both the Isle of Armor and The Crown Tundra expansions, as well as any updates or events associated with them. The Expansion Pass offers players a chance to further explore the Galar region and discover new Pokémon, features, and adventures.

The Expansion Passes for Pokemon Sword and Shield do not have an expiry date and you can buy them at any time. In fact, this is currently the only way to purchase the DLC for Pokemon since both Isle of Armor and Crown Tundra cannot be bought separately.