OBJECTIVE: To assess patient experiences of pain management during medical abortion up to 10 weeks' gestation with opt-in versus universal codeine provision. METHODS: We invited patients who underwent medical abortion up to 10 weeks of gestation to participate in an online, anonymous, English-language survey from November 2021 to March 2022. We performed ordinal regression analyses to compare satisfaction with pain management (5-point Likert scale) and maximum abortion pain score (11-point numerical rating scale) in the opt-in versus universal codeine provision groups. RESULTS: Of 11 906 patients invited to participate, 1625 (13.6%) completed the survey. Participants reported a mean maximum pain score of 6.8±2.2. A total of 1149 participants (70.7%) reported using codeine for pain management during their abortion. Participants in the opt-in codeine provision group were significantly more likely to be satisfied with their pain management than those in the universal group (aOR 1.48, 95% CI 1.12 to 1.96, p<0.01). Maximum abortion pain scores were lower on average among the opt-in codeine provision group (OR 0.80, 95% CI 0.66 to 0.96, p=0.02); however, this association was not statistically significant in the model adjusted for covariates (aOR 0.85, 95% CI 0.70 to 1.03, p=0.09). CONCLUSION: Our findings suggest that patients have a better experience with pain management during medical abortion when able to opt-in to codeine provision following counselling versus receiving this medication routinely.