Whilst increasingly widespread, teaching online can be a solo endeavour. In this paper, we consider how peer exchange between online tutors from different institutions may offer a solution to this professional isolation. We report on a cross-institutional peer observation and mentoring programme between the Universities of York (UK) and Waikato (New Zealand), designed to support tutors' personal development through online peer exchange. Our findings reveal that tutors' use of synchronous conferencing tools was influential in shaping the relationship between participants on the programme. Exposure to diversity served to challenge institutional pedagogical norms. We review the engagement strategies and emergent learning outcomes for participants, and discuss the necessary conditions of openness and commitment for effective peer exchange between online tutors from different cultural and institutional contexts.