Excess choice has previously been shown to have detrimental effects on decisions about consumer products. As the number of options increases, people are more likely to put off making an active choice (i.e., defer) and show less satisfaction with any purchase actually made. We extend this line of enquiry to choosing a charitable organisation to volunteer for. The issue is important because the number of voluntary organisations is enormous and the impact of such a decision may be greater than for consumer decisions in terms of time commitment and benefits to the volunteer and society. Study 1 asked students to examine a real volunteering website and record how many organisations they considered, decision difficulty and whether or not they would like to sign up for a chosen organisation or prefer to defer a decision. Study 2 presented either a relatively small (10) or large (30) choice set of hypothetical organisations and measured deferment likelihood and decision difficulty. In both studies the more options considered, the greater the likelihood to defer. This effect was mediated by decision difficulty. This research is the first to find that detrimental effects of excess choice extend to volunteering. Implications for volunteer recruitment are discussed.