Paytm FASTag FAQs: How to deactivate it, get a new tag, and all that you need to know
Paytm FASTag: Under the new One Vehicle, One FASTag initiative, each FASTag can only be linked to a single vehicle, and vice versa. As a result, users must deactivate their existing FASTag in order to obtain a new one.
Source: moneycontrol.com