To reset your Citibank debit card PIN online, you can call our toll-free helpline at 1-(888)-388-4751 (USA) or log into your Citibank online account or mobile app. Once logged in, go to the account settings or security section and choose the option to manage your PIN. Follow the instructions to verify your identity, which may involve receiving a verification code via email or SMS. Enter the verification code and set your new PIN. If you experience any difficulties, you can contact Citibank debit card support at 1-(888)-388-4751 for assistance.