You can't. If you want to apply for installment, the installment amount is set at 100% of your credit card's permanent limit. If you only have a permanent limit of 5000 yuan, the maximum installment amount is 5000 yuan, even if you save more money, you can't apply for this installment. However, there is no other way. You can save the money in your card before buying a mobile phone. For example, you saved 288 yuan and brushed 5288 yuan to buy a mobile phone, although it is impossible to handle the staging of China Mobile and China Construction Bank. But in the future, you can spend your application for the bill of China Construction Bank in installments.

Bill installment refers to applying to the bank for the installment payment of the bill consumption amount (above 500 yuan) during the period from the second day after the bill date to the final repayment date (once every 30 days), with the maximum not exceeding 90% of the total RMB consumption in the bill.

Suppose you deposit 288 and swipe 5288' s mobile phone, and the bill amount this month is 5000 (the overdraft amount is deducted from 288' s deposit first), and the maximum amount you can apply for during this period is 4500. At present, CCB's bill installment also has a handling fee discount. You're only doing this for installment payment.