The initiative, which Pret has claimed is the UK’s first in-shop coffee subscription, went live on 8 September and reflects part of the group's strategy to attract more customers post lockdown.
YourPret Barista gives users up to five ‘barista-prepared’ drinks per day for a fixed monthly price of £20, with the first month currently being offered for free to all subscribers.
Speaking to The Guardian, Pret chief executive Pano Christou said the company had seen 16,500 people sign up to the scheme by 3pm on first day.
"That beats our target," he said.
"We thought we’d do 2,000 or 3,000 on the first day.”
Pret has become somewhat emblematic of the struggles currently faced by high street chains as a result of the impact caused by the Coronavirus pandemic.
Last month the company was forced to make nearly 3,000 staff redundant after 30 of its branches were shuttered permanently as part of a major restructuring.
At the time the group also reported that the pandemic had set sales back 10 years.
In response, Christou is currently working to evolve Pret into a 'multi-channel business' with dark kitchens, more suburban sites and a shift into retail all planned.
Next month, Pret will start selling bags of coffee in Waitrose, and plans to launch a range of pre-packaged food in other major retailers in the new year.
The chain is also building up its delivery business through Deliveroo, Uber Eats and Just Eat and recently opened its first dark kitchen site in Colindale, north London, with more sites in the pipeline.
It has begun trialling a scheme popular in the US too, where offices have 'Pret Office Drops' that allow workers to order food through an app and collect it from Pret shelving installed in their office.
There are also plans to open more suburban sites, with Pret currently in the process of developing a hot dinner menu to deliver meals to people's homes.
"We need to move fast, we need to evolve, we need to innovate, and I think we need to take some risks," Christou added to The Guardian
“If we sit and wait for things to change, that is a bigger risk than going out there and being bold.”