Postcards

Postcards are cards that can always be sent to other players, and bought for 10 coins each, in the Postcard Catalog. The categories for postcards are invitations and encouragements. Some postcards are related to Club Penguin Rewritten's theme for the month. Other invitations include the Pizza Parlor, the Coffee Shop, the Dance Club, the Snow Forts, the Ice Rink, Sled Racing, the Ski Lodge, Mancala, Cove, and Find Four.

On February 3, 2020, an update was made which removed the delay when switching between postcards. Additionally, the player is no longer taken back to the beginning of their postcard list if they remove a postcard.

Trivia

 * When receiving the Happy Christmas Postcard from another penguin, you can click it to open the gift and reveal a free Candy Cane Hat for you to collect.
 * This also applies to the Happy Holidays Postcard however you get a Holiday Toque instead.
 * It is impossible to retrieve a postcard if it has been deleted.
 * Postcards were used to help express opinions during the 2017 Color Vote.
 * Penguins that weren't Secret Agents can still join the Elite Penguin Force by receiving a special postcard from an EPF agent.
 * From March 3, 2019, penguins are able to receive monthly 'checks' by being a secret agent for the PSA or EPF, and by being a Tour Guide. The PSA and Tour Guide postcards both give 250 coins, while the EPF postcard gives 350, making a total of 850 coins if you are part of all three.
 * Mascots usually don't give out postcards to players, however, there have been rare occasions where they have.
 * From January 21, 2021, players can store up to 200 postcards in their mailbox.

Glitches

 * There is a glitch, that, sometimes the name of the postcards are sent by the name "undefined".
 * Since the Buddy List update trying to send a postcard using the "New Message" option shows a blank screen.