Hi i im a maxis user with 1 main line and 2 subline under my account. So my mainline have a device contract. So i wana ask let say i wana buy another device with my subline number but after get the device i use different maxis number simcard, can maxis track it or brick the device or block it? Even if i pay the monthly device commitment without fail?
Need some advise. Thanks.

Telco will not bother which sim you used as long as you paid for the monthly commitment.

Should you have failed to make payment for x amount of time as per agreed in the contract, Telco will perform IMEI Phone Network lockdown and only will unlock it after you have made payment along with the penalty to reinstate it.

They wont care as long as you pay …
But nowadays most device comes with unremovable app that will remind you if you late on payment …

If you let you parents use the phone, they will be reminded that your bill is overdue…