The family was eight years into a Dubai posting. The eldest was halfway through the IB Diploma at GEMS Wellington. The younger was a Year 7 student at the same school. A bank repositioning meant a London move in the next academic year. The IB continuity question shaped every school decision and almost overrode the neighbourhood one.
The brief, as they framed it
"We've invested eight years in this curriculum. We want the eldest to finish the Diploma. We want the younger to keep the IB option open through to Year 11 minimum, with the realistic option of switching to A-Levels if it suits her better." The brief was specific enough to disqualify around 60% of London independent schools immediately.
Shortlist mechanics
London has roughly 23 IB World Schools across primary and secondary, but the schools offering the full Diploma cohort that an eldest mid-cycle child needs are concentrated in a smaller set: Southbank International, ACS Cobham/Hillingdon, ICS London, North London Collegiate, King's College School Wimbledon, and a handful of others. The family contacted seven schools by email between January and March, asking specifically about mid-Diploma transfers, subject availability at HL, and predicted-grade portability from the Dubai school. Three responded substantively. Two said "we don't typically take Diploma transfers" outright. Two never responded.
The decisive factor
For the eldest, subject availability at Higher Level was decisive. She was taking HL Mathematics Analysis and Approaches, HL Chemistry, and HL English Literature. Two of the three responsive London schools could offer the same combination. The third would have required a subject swap, which the IB rules technically allow but in practice creates a six-month catch-up problem. The family chose Southbank International (Westminster campus) for the eldest based on subject fit, despite a longer commute. The younger went to a closer school in West London with a similar IB pathway.
What they would do differently
"We left the school search too late. By the time we contacted schools in January, two of the three Diploma slots we wanted had been filled by other inbound families. If we'd started in October, we would have had more options. The other thing we underestimated was housing-school sequencing. We rented near the eldest's school assuming it would also serve the younger, then realised the journey for the younger was 45 minutes door to door."
What worked
The Dubai school sent an exceptionally thorough transcript pack, including predicted grades, sample work, and a teacher narrative for each subject. The London school flagged this as the strongest documentation they had seen from an inbound IB transfer. "Ask your current school for the full pack early. Don't accept a one-page transfer slip."