To talk to Citibank customer service, call their toll-free number, which is found on the back of your Citibank card or on their official website. For faster assistance, you can use the live chat feature on their website or the Citi Mobile App. Additionally, you can visit a local branch for in-person support. Citibank’s customer service is available 24/7 to help with various inquiries, including account issues, transactions, and general banking questions. For secure communication, you can also send a message through your online account portal.