Purpose– The relationship between accessing indecent images online and the perpetration of contact child sex offences remains unclear. The purpose of this paper is to provide a better understanding of the offence process of offenders who have both such convictions.Design/methodology/approach– A total of eight semi-structured interviews were conducted with older adult males who had downloaded indecent images and also had a history of contact sex offences against children. Data analysis involved thematic coding based on guidelines suggested by Braun and Clarke (2006).Findings– Themes which emerged suggest some similarities (offence process behaviours), but also some differences (developmental factors) between the eight offenders. Data relevant to developmental factors formed two primary themes: childhood attachment difficulties and experiences of childhood abuse, both of which appeared to influence the offence process. Escalating factors generated a further three themes: adult relationships, personality problems and substance use. Five main categories also emerged with regard to offence behaviours: sexually deviant interests, lack of self-control, opportunity, the role of the internet (availability, easy access and anonymity), and cognitive distortions (justifications: interest in challenge and sexual frustration; denial: accidental access and denial of a victim, normalisation; blame: blame on the victim, new technologies and authorities and blame on other factors; and minimisation).Practical implications– A better understanding of the offence process would inform clinical practice with such offenders and aid in the process of prevention.Originality/value– This is the first research to date which explores the rationale provided for their behaviour by those convicted of both internet and contact child sex offences.