Aim <p>The aim of this study is to analyse to which extent descriptive norms from personal networks and the general population, as well as personal norms, influence non-compliance during public health crises like the COVID-19 pandemic. Further we argue that descriptive norms exert a stronger effect when the reference group is one’s social network rather than the general population.</p> Subject and methods <p>The behaviour investigated is vaccination certificate falsification and breaking the norm of self-isolation while experiencing COVID-19 symptoms. Subjects from 26 European countries were interviewed via an online survey (<i>N</i> = 1,006). For analysis we used multiple logistic regression.</p> Results <p>Our results show that the likelihood of non-compliance increases with weak descriptive norms. An individual is also more likely to engage in non-compliance when possessing low personal norms. Only limited evidence was found for our expectation that descriptive norms within personal networks have a greater influence on individual behaviour compared to those of the general population. We also found no evidence suggesting an interaction effect between personal norms and descriptive norms.</p> Conclusion <p>Although descriptive norms from the social network do not have a stronger effect, descriptive norms related to both the personal network and the general population play a major role in influencing non-compliance and should therefore be considered when planning public health measures.</p>