diff --git a/src/Meezi.Infrastructure/Data/PlatformDataSeeder.cs b/src/Meezi.Infrastructure/Data/PlatformDataSeeder.cs
index 7005983..a22bde2 100644
--- a/src/Meezi.Infrastructure/Data/PlatformDataSeeder.cs
+++ b/src/Meezi.Infrastructure/Data/PlatformDataSeeder.cs
@@ -422,9 +422,12 @@ public static class PlatformDataSeeder
             }
         };
 
-        var existingIds = (await db.PlatformPlanDefinitions.Select(p => p.Id).ToListAsync())
-            .ToHashSet(StringComparer.Ordinal);
-        var missing = plans.Where(p => !existingIds.Contains(p.Id)).ToArray();
+        // Tier (not Id) carries the unique constraint, so dedupe on Tier — an
+        // existing Free plan may have a different Id, and inserting another
+        // Free-tier row would violate IX_PlatformPlanDefinitions_Tier.
+        var existingTiers = (await db.PlatformPlanDefinitions.Select(p => p.Tier).ToListAsync())
+            .ToHashSet();
+        var missing = plans.Where(p => !existingTiers.Contains(p.Tier)).ToArray();
         if (missing.Length == 0) return;
 
         db.PlatformPlanDefinitions.AddRange(missing);
@@ -459,9 +462,10 @@ public static class PlatformDataSeeder
             F("discover_profile", "پروفایل کشف", "Discover profile", "growth")
         };
 
-        var existingIds = (await db.PlatformFeatures.Select(f => f.Id).ToListAsync())
+        // Key carries the unique constraint, so dedupe on Key (not Id).
+        var existingKeys = (await db.PlatformFeatures.Select(f => f.Key).ToListAsync())
             .ToHashSet(StringComparer.Ordinal);
-        var missing = features.Where(f => !existingIds.Contains(f.Id)).ToArray();
+        var missing = features.Where(f => !existingKeys.Contains(f.Key)).ToArray();
         if (missing.Length == 0) return;
 
         db.PlatformFeatures.AddRange(missing);