What is the minimum age to sign up a plan with Grid Mobile? Admin August 16, 2019 06:58 Updated Follow You have to be at least 16 years of age to sign up using your own ID. Related articles What are the documents Grid Mobile accept upon signing up? Are there charges that I have to take note of when I register for a new account? Do I have to sign up a 12 or 24 months contract? Comments 0 comments Please sign in to leave a comment.