Yes, there is a 15-day grace period for commercial Bitrix24 Cloud accounts that weren't able to renew subscription for any reason (updating card information, expired card, pending wire transaction, etc.). During the grace period, Bitrix24 accounts remain active and do not roll back to the Free plan. The 15-day grace period is enabled automatically after your commercial subscription expires.
Please note that the grace period is not activated after your free 15-day trial is over.
