Upgrading to Visible+ with Sim on my own phone

[Khansen]

I received a sim from Visible in the mail when I switched my plan from Canadian to U.S. based. I am hoping to temporarily switch to Visible+ in order to contact relatives living internationally. Do I need to get another sim or can I simply switch plans online? 

Thanks 

[TheCellTower]

I believe you can simply change the plan because it's the same network.