The retailer Poundland has raised more than £1m for Macmillan Cancer Support over the past five years.
The low-cost retailer said employees and customers had raised £1,035,000 for the charity since Poundland began supporting it in 2009.
Staff at the stores have carried out fundraising challenges including the Three Peaks Challenge, in which participants had to climb the highest peaks in Scotland, England and Wales – Ben Nevis, Scafell Pike and Snowdon – in less than 24 hours.
Other fundraising activities by Poundland staff have included a cycle ride from London to Paris and running the London Marathon.
The retailer also sold a range of charity products from which a proportion of the sale price went to Macmillan.
The two organisations are this week marking the milestone by running a roadshow that will involve in-store activities, including the opportunity for customers to have their photographs taken with giant pound coins in the outlets that have helped to raise the most funds.
Jim McCarthy, chief executive of Poundland, said: "Our customers and colleagues have voted to continue to support Macmillan since 2009, and we have seen some fantastic members of our team going above and beyond for a charity that has touched many of us personally."
The money raised will help to fund the practical, emotional, medical and financial support provided by the charity to people affected by cancer.