diff --git a/pipeline/transform/models/marts/dim_school.sql b/pipeline/transform/models/marts/dim_school.sql
index 9dead72..014acbe 100644
--- a/pipeline/transform/models/marts/dim_school.sql
+++ b/pipeline/transform/models/marts/dim_school.sql
@@ -14,7 +14,14 @@ select
     s.urn,
     s.local_authority_code * 1000 + s.establishment_number as laestab,
     s.school_name,
-    s.phase,
+    case
+        when s.phase is not null and s.phase != 'Not applicable' then s.phase
+        when s.statutory_high_age is not null and s.statutory_high_age <= 11 then 'Primary'
+        when s.statutory_low_age is not null and s.statutory_low_age >= 11 then 'Secondary'
+        when s.statutory_low_age is not null and s.statutory_high_age is not null
+             and s.statutory_low_age < 11 and s.statutory_high_age > 11 then 'All-through'
+        else s.phase
+    end as phase,
     s.school_type,
     s.academy_trust_name,
     s.academy_trust_uid,