Teacher Shortages in International Schools: What the Data Shows
Jamal Lewis
Every IB coordinator who has struggled to find short-notice cover for a class already knows, from direct experience, that staffing has gotten harder. What's less visible from inside a single school is how consistent that experience is across the sector, and how much of it is a structural feature of the international school market rather than a problem specific to any one school's hiring practices. The most reliable data here doesn't come from general global education statistics, which tend to be dominated by shortages in national systems in the developing world, it comes from research focused specifically on international schools, and that data tells a clear, sector-specific story about why coverage planning has become something schools need a real strategy for.
A Market That Has Grown Faster Than Its Teacher Supply
The international schools sector has expanded rapidly. According to ISC Research, the specialist data provider for this market, international schools now employ over 713,000 staff members worldwide, up from roughly 626,800 full-time teachers in 2023 and 556,150 in 2018 and a 13% increase in just five years even before more recent growth is factored in. That expansion has occurred across a market of more than 14,000 international schools, with some of the fastest teacher-employment growth concentrated in regions like South-Eastern Asia, where the teaching workforce grew by 28% over the same five-year window. Growth on that scale would strain any recruitment pipeline, and ISC Research's own specialist reporting projects a need for up to roughly 158,000 additional teachers by 2028 if the market continues to recover toward its pre-pandemic growth trajectory.
The practical effect for an individual school is straightforward: the pool of experienced, readily available international educators has not kept pace with the number of open positions across the sector, which means schools that once could rely on a deep local bench of qualified substitutes now compete for the same limited supply as everyone else.
Retention Is the Other Half of the Problem
Recruitment difficulty is only part of the picture retention has become just as significant a driver of the staffing gap. ISC Research's Teacher Movement Survey, which drew responses from more than 2,500 teachers across 59 countries, found that most international school teachers can only be expected to stay in a given post for one to six years, with close to half of respondents saying they planned to move on from their current role within that window. That level of turnover is a structural feature of international teaching, driven largely by teachers' own reasons for entering the sector in the first place travel, cultural exploration, and career variety rather than dissatisfaction alone, but it still means schools are managing a meaningfully higher baseline rate of departures and transitions than a typical national school system would see.
Wellbeing and workload pressures have compounded this. Sector reporting has described teacher wellbeing in international schools as being at a low point, driven by heavy workloads and limited professional support, contributing to elevated departure rates severe enough that international bodies have described the situation as a genuine shortage alert affecting schools across the sector. None of this is unique to any single region or curriculum, it shows up consistently across the reporting on international education as a whole, IB schools included.
Why This Matters More for Coverage Than for Hiring Alone
Most of the public conversation around these figures focuses on recruitment: how a school competes for candidates during its annual hiring cycle. Less attention goes to what happens between hiring cycles, when an already-thin staffing bench has to absorb an unplanned absence, a sudden departure, an extended leave, a visa delay for an incoming hire. A tighter overall market and a higher baseline turnover rate both make that in-year gap harder to fill quickly with a like-for-like replacement. A school that a decade ago could find a specialist short-term substitute within days, drawing on a deeper and more stable local pool of experienced international educators, is now more likely to face a longer gap, a less specialized substitute, or no substitute at all. That raises the stakes on everything a school can control directly: clear pacing documentation, structured independent work for students, and real visibility into how a class is performing while a gap is being filled, rather than relying on the assumption that a naturally available substitute will be there when needed.
Reading the Trend Line Correctly
None of this data suggests the pressure on international school staffing is about to ease. Growth projections point toward continued demand for teachers through the rest of the decade, and the underlying retention pattern, a workforce that turns over substantially within a five- to six-year window as a matter of course isn't the kind of thing that reverses quickly even if recruitment itself becomes easier. For IB coordinators and school leaders, the practical takeaway isn't alarm, it's a reason to treat coverage planning as infrastructure rather than improvisation. Schools that build a repeatable process for absences, keep pacing and performance data current enough to hand off quickly, and don't rely solely on finding a perfect subject-specialist substitute on short notice are the ones best positioned to absorb a market that, by every measure specific to this sector, isn't getting any looser.