When you buy a device on the +Phone plan, the cost of your device is split between an upfront amount and monthly installments. The monthly device installment is always at $37 over 24 months ($888 in total).
The entire installment amount of $888 is blocked on your card when you purchase your device. Every month after your purchase, $37 will be charged on the 1st calendar day of the month and the blocked amount on your card will be reduced by $37 after each successful device installment payment for the next 24 months until the device installment is completed.
*Important note: In the event of plan suspension (regardless of voluntary or involuntary), the full amount of the device will automatically be charged in full on your credit card.