• The effects of web page donation link (donation button) design on aid agency transactional trust was examined in a survey and in two experiments. Experiment 1 compared three donation button designs, which were developed on the basis of study 1, which was a survey of 559 charity websites, and found no significant effects on rated transactional trust. Experiment 2 attempted to manipulate transactional uncertainty through donation button design by incorporating crisis/need and aid agency response photographs. These button design manipulations significantly increased rated transactional trust. In both experiments, transactional trust ratings were significantly correlated with donation compliance ratings. These results suggest that transactional trust can be enhanced through the considered design of the donation button, and increasing transactional trust in this manner may result in more online donations.