The FRSB today released its ruling about the charity, which provides cleft lip and palate surgery to children in developing countries.
The ruling, which reached the third and final complaint stage, concerned envelopes issued by the charity that said "make one gift now and we’ll never ask for another donation again!"
The FRSB’s board decided that this did not breach the Institute of Fundraising’s Direct Mail Code of Fundraising Practice or the Fundraising Promise, although the verdict was not unanimous. The adjudication report notes that it was "a borderline case".
It says the appeal slogan did not pressure people into donating because the material in the envelope said people could be removed from Smile Train’s mailing list without giving.
The board recommended that Smile Train should put this opt-out clause on the outside of the envelope.
At the first stage of the process Smile Train apologised to the complainant for the fact they felt threatened by the mailshot slogan and for not erasing them from their mailing list.
During the adjudication process, the FRSB and the complainant suggested that Smile Train change the wording of the envelope but it declined, citing the success of the campaign and positive feedback from the public.
The complaint went to the board after an FRSB compliance manager thought the mailshot could be in breach of the code and the promise.
Four other complaints were made about the same tagline between September and October 2011 and a fifth one was found not to be a breach of the code in September 2010.
Colin Lloyd, chair of the Fundraising Standards Board, said: "Charities have a tough job in making their brand stand out from the crowd and to capture people’s attention, but it is crucial that people do not feel pressured into giving.
"Smile Train has taken an unusual approach with its One Gift campaign and we understand that it has been the charity’s most successful appeal. We were reassured that the mailing contains all the necessary information to clarify the slogan on the front cover, but we hope to see greater clarity on the envelope itself in future."
The FRSB said Smile Train was open and transparent during the investigation.
Smile Train did not respond to requests for comment.