A survey found that 38 per cent of 25 to 34-year-olds and nearly a third of 16 to 24-year-olds would give to charity by text.
But only 5 per cent of people surveyed had done so in the past month, with 58 per cent saying they were put off by mobile phone charges.
This is the first piece of research for a coalition led by the Institute of Fundraising and the Charities Aid Foundation that is campaigning for cost-effective text donations.
Joe Saxton, co-founder of think tank nfpSynergy, which carried out the research, said: "This shows that the fundraising potential of texting may be substantial, but donors find costs prohibitive."
The coalition hopes to prove to mobile companies that more people would donate by text if charges were reduced.