Understanding farmers’ intentions to use new technologies for agricultural data collection is essential in developing digital citizen science in agriculture. While more advanced technologies are available, to reach smallholder farmers simple technologies such as mobile SMS are needed. The main objective of this study was to explore the acceptance of mobile SMS technology by smallholder farmers to provide farm related information. A second objective was to assess the role of farmer’s characteristics (i.e., age and experience) in predicting farmers’ intentions to adopt mobile SMS. This study extended the unified theory of acceptance and use of technology (UTAUT2) model with constructs from trust, personal innovativeness in information technology and mastery-approach goals. The sample (N = 220) consisted of a group of smallholder farmers from three Ethiopian regions involved in a mobile SMS experiment and a control group. Structural equation modelling showed that intentions to adopt mobile SMS technology for agricultural data provision were predicted by the perceived usefulness of the technology (performance expectancy), the effort needed to use the technology (effort expectancy), the cost of using the technology (price value) and the trustworthiness of the organising body (trust; e.g., organisations behind the citizen science initiative). Multi-group analysis using farmer’s age and experience as moderator variables further revealed that performance expectancy was important for younger farmers, whereas price value was important for farmers who did not participate in a mobile SMS experiment. This study generates useful information and implications for citizen science practitioners, policy makers and mobile application developers by identifying the driving factors for farmers to adopt mobile SMS for agricultural data collection.