The unlockable costumes in Resident Evil CODE:Veronica are few in number. To date, there has only been one unlockable costume across all versions of the game.
There is no method to obtaining alternate outfits in the main game, as no secret closet or option to change exists. The unlockable costumes are only available in the Battle Game that is unlocked after completing the game once on any difficulty with any rank.
By completing the Battle Game once with an A, B, C, D, or E rank using Claire, her alternate outfit becomes available. This outfit cannot be worn in the main game. In this outfit, Claire is equipped with the Combat Knife; Grenade Launcher; Assault Rifle; infinite Grenade, Flame, and Acid Rounds; and one Mixed Herb (G/R/B).
Claire wears a set of Umbrella clothing for this costume. The design of the outfit is similar to her standard outfit in Resident Evil 2, consisting of a red vest and shorts. Her outfit has white and black accents, a black top underneath her vest, and "Umbrella" written across both sides of her shorts. Claire also wears a pair of white-framed sunglasses at the top of her head, Umbrella logo earrings, and a pair of white boots.
- In the HD release, Claire's "logo"—the "Let Me Live" Valkyrie—is replaced with the umbrella she holds in her result screen. Her portrait is also updated to reflect the costume change, unlike previous versions of the game where Claire's standard menu portrait is reused.
- CODE: Veronica is the first title in the series to feature alternate versions of characters with different costumes and equipment in its respective battle game. This is later revisited in Resident Evil 5 with The Mercenaries.