You can purchase a mobile phone by installment payment in the following ways:

1. Use the installment service provided by the e-commerce platform. Select the mobile phone you want to buy on e-commerce platforms such as Taobao, Tmall, JD.com, etc., and select the installment payment option during checkout. These platforms usually support credit card installments (such as Huabei installments, JD Baitiao installments) and consumer loan installments (such as Fenqile). After choosing installment payment, you need to confirm the order information, including the period of installment payment (such as 3 installments, 6 installments or 12 installments), and submit the order.

2. Purchase through the official website of the mobile phone brand or official flagship store. Select your favorite mobile phone model on the mobile phone brand's official website or official flagship store, and then choose installment payment as the payment method. Apple's official website is an example, which supports credit card installment purchases of mobile phones.

3. Pay in installments through physical stores. If you choose to purchase a mobile phone by installment in a physical store, you need to bring your ID card, bank card (credit card overdraft limit must be greater than the price of the mobile phone) and other necessary documents and information. In some cases, if you have a social security card or driver's license, it can also be used as proof of identity.