diff --git a/internal/db/db.go b/internal/db/db.go
index a9e4da6..4e315d2 100644
--- a/internal/db/db.go
+++ b/internal/db/db.go
@@ -134,6 +134,14 @@ type DB interface {
 	// In case of no entries, a 'no entries' error will be returned
 	GetLastStatusForAccountID(accountID string, status *model.Status) error
 
+	// IsUsernameAvailable checks whether a given username is available on our domain.
+	// Returns an error if the username is already taken, or something went wrong in the db.
+	IsUsernameAvailable(username string) error
+
+	// IsEmailAvailable checks whether a given email address for a user is available on our domain.
+	// Returns an error if the email is already associated with an account, or something went wrong in the db.
+	IsEmailAvailable(email string) error
+
 	/*
 		USEFUL CONVERSION FUNCTIONS
 	*/