The company said in a blog post on Tuesday that this upgrade was part of its T22 modernisation plan.
An eSIM comes embedded in some phones like the iPhone, Samsung Galaxy S20, the Pixel line and the Motorola Razr..
Andrew Stormont, mobility executive - Product & Technology, said the change would take effect right away.
"The process takes less than two minutes. No more waiting around for an eSIM activation card to be sent through the post or having to travel to see someone face-to-face."