mobile data cost; packet charge
Refers to the cost incurred for mobile data usage, typically in the context of cellular data plans. Common in discussions about smartphone bills.
I watched too many videos this month and my data charges went up.
I try to use Wi-Fi to save on data costs.
Compound of パケット (from English 'packet', referring to data packets in mobile networks) and 代 (charge, fee). The term became common with the rise of mobile internet and packet-based billing.