Charities will be allowed to take only 20 per cent of the total advertising on most train services in and out of London, according to the company responsible for managing on-board advertising on those routes.
Ian Reynolds, managing director of KBH On-Train Media, said that charities would be limited to 12,000 out of the approximately 60,000 advertising panels available on trains from 22 April.
He said the decision had been taken because the past year had seen "a huge explosion" in the amount of charity advertising on trains, with 20 large charities running up to five or six campaigns.
"In some carriages, more than half of the advertising is charity appeals, all crying out for people to donate," he said.
Reynolds said the decision to limit charity advertising had been taken partly in response to feedback from charities themselves, because they felt a large number of appeals running at the same time reduced the effectiveness of them all.
"This decision certainly hasn’t been taken because we’ve had complaints or we’re worried that charity advertising is dragging down the quality," he said. "We just want to make sure there’s equal distribution of the campaigns so they aren’t cannibalising one another’s responses."
Reynolds said he did not expect the restriction to affect the total amount of charity advertising in the year, but to reduce it at peak periods. At present, charity advertising is particularly concentrated on November and December, he said.
He said he thought on-train advertising by charities had grown because they could now attract an instant response through text messages.
"We’ve seen them double their spend," he said. "Posters have traditionally not been good for marketing that asks for a direct response, but people are beginning to do so much more with their mobile phones. Most posters ask for a text response."