Charitable donations by text message fell by £7m last year, figures from the industry regulator show.
The annual report of the Phone-paid Services Authority, which regulates goods and services charged to phone bills, such as TV voting lines, shows that charity text giving was worth £115m in the year to the end of March, compared with £122m in the previous year.
The decline comes despite the regulator, which was previously called PhonePay Plus, predicting last year that charitable text donations would grow in 2016/17 to £129m.
The 2015/16 figures were a 28 per cent increase on those for 2014/15, due in part to viral campaigns including the Ice Bucket Challenge and No-Make-up Selfie.
No explanation is offered by the PSA in the latest report for the fall.
The area remained the largest individual sector regulated by the PSA, ahead of online competitions or quizzes on £70m, games on social networks on £66m and directory enquiries on £65m.