In March, JustGiving announced it was abolishing its fee of 5 per cent, which it charged on all donations made through its platform, and replacing it with a system in which donors could choose to add voluntary tips to their donations.
Most charities now have the option on their JustGiving donation pages for donors to add either fixed 5 per cent tips or tip amounts of their choice.
Macmillan is the only charity in the top 50 organisations on the Third Sector Charity Brand Index of the UK’s best-known charities not to have this option on its JustGiving donation page.
Hannah Mahoney-Smith, head of supporter care at Macmillan Cancer Support, told Third Sector: "Since the new voluntary contribution model was introduced by JustGiving in March, we have been working to understand what it means for our supporters and, in the meantime, we are continuing to pay a percentage fee to JustGiving."
She declined to comment on why the charity had not moved to the new tip system or say whether the charity had insisted upon it.
She said the existing arrangement was reaching the end of its term and the charity was in the process of discussing its future arrangements with JustGiving.
"Keeping our existing arrangements with JustGiving for the three months since the new model came into effect has given us time to understand the overall benefits and how this will work best for our supporters and people living with cancer," Mahoney-Smith said.
A spokesman for JustGiving said the voluntary contributions model had enjoyed enormous support.
"No two charities are the same and we work individually with every organisation – big and small – to help build the right fundraising solution for them," he said.