British charities will likely take a fund-raising hit running into the millions of dollars if planned strikes by postal workers continue into the Christmas holiday, Third Sector Online reports.

“If there is a backlog in the postal system [due to strikes], people will receive a large amount of mail when the strike is over and may be less likely to read and respond to appeals,” said the report by the Institute for Fundraising, a professional development group that surveyed member organizations about their holiday prospects. “People want to give before Christmas, not after.”