diff --git a/.env.example b/.env.example
index 7d94cf136..ba56008f3 100644
--- a/.env.example
+++ b/.env.example
@@ -55,5 +55,3 @@ GOOGLE_CLIENT_SECRET=changeme
 # E2E tests can supply this to enable test utility endpoints
 RESEED_API_KEY=changeme
 
-# Enable immediate onboarding for schools
-ENABLE_IMMEDIATE_SCHOOL_ONBOARDING=true
diff --git a/app/models/school.rb b/app/models/school.rb
index 2f14500b0..d57530e1a 100644
--- a/app/models/school.rb
+++ b/app/models/school.rb
@@ -49,8 +49,7 @@ class School < ApplicationRecord
 
   before_save :format_uk_postal_code, if: :should_format_uk_postal_code?
 
-  # TODO: Remove the conditional once the feature flag is retired
-  after_create :generate_code!, if: -> { FeatureFlags.immediate_school_onboarding? }
+  after_create :generate_code!
 
   def self.find_for_user!(user)
     school = Role.find_by(user_id: user.id)&.school || find_by(creator_id: user.id)
@@ -72,9 +71,7 @@ def rejected?
   end
 
   def verify!
-    # TODO: Remove this line once the feature flag is retired
-    generate_code! unless FeatureFlags.immediate_school_onboarding?
-
+    generate_code!
     update!(verified_at: Time.zone.now)
   end
 
diff --git a/app/models/teacher_invitation.rb b/app/models/teacher_invitation.rb
index 68576b5b7..c93a67195 100644
--- a/app/models/teacher_invitation.rb
+++ b/app/models/teacher_invitation.rb
@@ -6,7 +6,6 @@ class TeacherInvitation < ApplicationRecord
   belongs_to :school
   validates :email_address,
             format: { with: EmailValidator.regexp, message: I18n.t('validations.invitation.email_address') }
-  validate :school_is_verified, unless: -> { FeatureFlags.immediate_school_onboarding? }
   after_create_commit :send_invitation_email
   encrypts :email_address
 
@@ -16,12 +15,6 @@ class TeacherInvitation < ApplicationRecord
 
   private
 
-  def school_is_verified
-    return if school.verified?
-
-    errors.add(:school, 'is not verified')
-  end
-
   def send_invitation_email
     InvitationMailer.with(invitation: self).invite_teacher.deliver_later
   end
diff --git a/app/services/school_verification_service.rb b/app/services/school_verification_service.rb
index aaa3b7559..b469ad565 100644
--- a/app/services/school_verification_service.rb
+++ b/app/services/school_verification_service.rb
@@ -7,24 +7,20 @@ def initialize(school)
     @school = school
   end
 
-  def verify(token: nil)
+  def verify(token:)
     success = false
     School.transaction do
       school.verify!
 
-      # TODO: Remove this line, once the feature flag is retired
-      success = FeatureFlags.immediate_school_onboarding? || SchoolOnboardingService.new(school).onboard(token: token)
-
-      # TODO: Remove this line, once the feature flag is retired
+      success = SchoolOnboardingService.new(school).onboard(token: token)
       raise ActiveRecord::Rollback unless success
     end
+
+    success
   rescue StandardError => e
     Sentry.capture_exception(e)
     Rails.logger.error { "Failed to verify school #{@school.id}: #{e.message}" }
     false
-  else
-    # TODO: Return 'true', once the feature flag is retired
-    success
   end
 
   delegate :reject, to: :school
diff --git a/lib/concepts/school/operations/create.rb b/lib/concepts/school/operations/create.rb
index ac6cdf96c..ff8e2521c 100644
--- a/lib/concepts/school/operations/create.rb
+++ b/lib/concepts/school/operations/create.rb
@@ -10,11 +10,8 @@ def call(school_params:, creator_id:, token:)
         School.transaction do
           response[:school].save!
 
-          # TODO: Remove this conditional once the feature flag is retired
-          if FeatureFlags.immediate_school_onboarding?
-            onboarded = SchoolOnboardingService.new(response[:school]).onboard(token:)
-            raise 'School onboarding failed' unless onboarded
-          end
+          onboarded = SchoolOnboardingService.new(response[:school]).onboard(token:)
+          raise 'School onboarding failed' unless onboarded
         end
 
         response
diff --git a/lib/concepts/school_student/create.rb b/lib/concepts/school_student/create.rb
index 1c0745d00..2954c4fb4 100644
--- a/lib/concepts/school_student/create.rb
+++ b/lib/concepts/school_student/create.rb
@@ -25,8 +25,7 @@ def create_student(school, school_student_params, token)
         validate(
           username:,
           password:,
-          name:,
-          school: (FeatureFlags.immediate_school_onboarding? ? nil : school)
+          name:
         )
 
         response = ProfileApiClient.create_school_student(token:, username:, password:, name:, school_id:)
@@ -35,13 +34,10 @@ def create_student(school, school_student_params, token)
         user_id
       end
 
-      def validate(username:, password:, name:, school: nil)
+      def validate(username:, password:, name:)
         raise ArgumentError, "username '#{username}' is invalid" if username.blank?
         raise ArgumentError, "password '#{password}' is invalid" if password.size < 8
         raise ArgumentError, "name '#{name}' is invalid" if name.blank?
-
-        return unless school
-        raise ArgumentError, 'school must be verified' unless school.verified?
       end
     end
   end
diff --git a/lib/feature_flags.rb b/lib/feature_flags.rb
deleted file mode 100644
index 86a76d637..000000000
--- a/lib/feature_flags.rb
+++ /dev/null
@@ -1,7 +0,0 @@
-# frozen_string_literal: true
-
-module FeatureFlags
-  def self.immediate_school_onboarding?
-    ENV['ENABLE_IMMEDIATE_SCHOOL_ONBOARDING'] == 'true'
-  end
-end
diff --git a/spec/concepts/school/create_spec.rb b/spec/concepts/school/create_spec.rb
index fd098540d..7b9927c3e 100644
--- a/spec/concepts/school/create_spec.rb
+++ b/spec/concepts/school/create_spec.rb
@@ -83,14 +83,7 @@
     end
   end
 
-  describe 'when immediate onboarding is enabled' do
-    # TODO: Remove this block once the feature flag is retired
-    around do |example|
-      ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'true') do
-        example.run
-      end
-    end
-
+  describe 'immediate onboarding' do
     let(:onboarding_service) { instance_spy(SchoolOnboardingService, onboard: true) }
 
     before do
@@ -102,24 +95,4 @@
       expect(onboarding_service).to have_received(:onboard).with(token:)
     end
   end
-
-  # TODO: Remove these examples once the feature flag is retired
-  describe 'when immediate onboarding is disabled' do
-    around do |example|
-      ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: nil) do
-        example.run
-      end
-    end
-
-    let(:onboarding_service) { instance_spy(SchoolOnboardingService) }
-
-    before do
-      allow(SchoolOnboardingService).to receive(:new).and_return(onboarding_service)
-    end
-
-    it 'does not call the onboarding service' do
-      described_class.call(school_params:, creator_id:, token:)
-      expect(onboarding_service).not_to have_received(:onboard)
-    end
-  end
 end
diff --git a/spec/concepts/school_student/create_spec.rb b/spec/concepts/school_student/create_spec.rb
index 1981f0a00..202b3815b 100644
--- a/spec/concepts/school_student/create_spec.rb
+++ b/spec/concepts/school_student/create_spec.rb
@@ -76,29 +76,6 @@
     end
   end
 
-  context 'when the school is not verified' do
-    let(:school) { create(:school) } # not verified by default
-
-    context 'when immediate_school_onboarding is FALSE' do
-      it 'returns the error message in the operation response' do
-        ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'false') do
-          response = described_class.call(school:, school_student_params:, token:)
-          expect(response[:error]).to match(/school must be verified/)
-        end
-      end
-    end
-
-    context 'when immediate_school_onboarding is TRUE' do
-      it 'does not error due to school verification' do
-        ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'true') do
-          response = described_class.call(school:, school_student_params:, token:)
-
-          expect(response[:error]).to be_nil
-        end
-      end
-    end
-  end
-
   context 'when the student cannot be created in profile api because of a 422 response' do
     let(:error) { { 'message' => "something's up with the username" } }
     let(:exception) { ProfileApiClient::Student422Error.new(error) }
diff --git a/spec/concepts/school_teacher/invite_spec.rb b/spec/concepts/school_teacher/invite_spec.rb
index 231d8cbda..31f851c3f 100644
--- a/spec/concepts/school_teacher/invite_spec.rb
+++ b/spec/concepts/school_teacher/invite_spec.rb
@@ -49,26 +49,4 @@
       expect(Sentry).to have_received(:capture_exception).with(kind_of(StandardError))
     end
   end
-
-  context 'when the school is not verified' do
-    let(:school) { create(:school) }
-
-    context 'when immediate_school_onboarding is FALSE' do
-      it 'does return an error message in the operation response' do
-        ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'false') do
-          response = described_class.call(school:, school_teacher_params:, token:)
-          expect(response[:error]).to match(/is not verified/)
-        end
-      end
-    end
-
-    context 'when immediate_school_onboarding is TRUE' do
-      it 'does not return an error message in the operation response' do
-        ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'true') do
-          response = described_class.call(school:, school_teacher_params:, token:)
-          expect(response[:error]).to be_blank
-        end
-      end
-    end
-  end
 end
diff --git a/spec/lib/feature_flags_spec.rb b/spec/lib/feature_flags_spec.rb
deleted file mode 100644
index b7fa7b085..000000000
--- a/spec/lib/feature_flags_spec.rb
+++ /dev/null
@@ -1,37 +0,0 @@
-# frozen_string_literal: true
-
-require 'rails_helper'
-
-RSpec.describe FeatureFlags do
-  describe '.immediate_school_onboarding?' do
-    it 'returns true when ENV is set to "true"' do
-      ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'true') do
-        expect(described_class.immediate_school_onboarding?).to be(true)
-      end
-    end
-
-    it 'returns false when ENV is not set' do
-      ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: nil) do
-        expect(described_class.immediate_school_onboarding?).to be(false)
-      end
-    end
-
-    it 'returns false when ENV is set to empty string' do
-      ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: '') do
-        expect(described_class.immediate_school_onboarding?).to be(false)
-      end
-    end
-
-    it 'returns false when ENV is set to "false"' do
-      ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'false') do
-        expect(described_class.immediate_school_onboarding?).to be(false)
-      end
-    end
-
-    it 'returns false when ENV is set to any other value' do
-      ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: '1') do
-        expect(described_class.immediate_school_onboarding?).to be(false)
-      end
-    end
-  end
-end
diff --git a/spec/models/school_spec.rb b/spec/models/school_spec.rb
index 06846060c..81bdbc06f 100644
--- a/spec/models/school_spec.rb
+++ b/spec/models/school_spec.rb
@@ -417,12 +417,6 @@
     end
 
     describe 'code validations' do
-      around do |example|
-        ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'true') do
-          example.run
-        end
-      end
-
       it 'requires #code to be unique' do
         school # ensure existing school has a code
         another_school = build(:school)
@@ -532,12 +526,6 @@
   end
 
   describe 'code generation' do
-    around do |example|
-      ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'true') do
-        example.run
-      end
-    end
-
     it 'automatically generates a code after creation' do
       new_school = described_class.create!(build(:school).attributes.except('id', 'created_at', 'updated_at'))
       expect(new_school.reload.code).to be_present
diff --git a/spec/models/teacher_invitation_spec.rb b/spec/models/teacher_invitation_spec.rb
index d1706e08e..0fdb4af94 100644
--- a/spec/models/teacher_invitation_spec.rb
+++ b/spec/models/teacher_invitation_spec.rb
@@ -18,24 +18,6 @@
     expect(invitation).not_to be_valid
   end
 
-  it 'is valid with an unverified school and immediate_school_onboarding is TRUE' do
-    ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'true') do
-      school = build(:school, verified_at: nil)
-      invitation = build(:teacher_invitation, school:)
-
-      expect(invitation).to be_valid
-    end
-  end
-
-  it 'is invalid with an unverified school and immediate_school_onboarding is FALSE' do
-    ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'false') do
-      school = build(:school, verified_at: nil)
-      invitation = build(:teacher_invitation, school:)
-
-      expect(invitation).not_to be_valid
-    end
-  end
-
   it 'sends an invitation email after create' do
     school = create(:verified_school)
 
diff --git a/spec/services/school_verification_service_spec.rb b/spec/services/school_verification_service_spec.rb
index 93ea0289b..e571ff714 100644
--- a/spec/services/school_verification_service_spec.rb
+++ b/spec/services/school_verification_service_spec.rb
@@ -14,173 +14,32 @@
   end
 
   describe '#verify' do
-    describe 'when immediate onboarding is enabled' do
-      # TODO: Remove this block once the feature flag is retired
-      around do |example|
-        ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: 'true') do
-          example.run
-        end
+    describe 'when school can be saved' do
+      it 'saves the school' do
+        service.verify(token:)
+        expect(school).to be_persisted
       end
 
-      describe 'when school can be saved' do
-        it 'saves the school' do
-          service.verify
-          expect(school).to be_persisted
-        end
-
-        it 'sets verified_at to a date' do
-          service.verify
-          expect(school.reload.verified_at).to be_a(ActiveSupport::TimeWithZone)
-        end
-
-        it 'returns true' do
-          expect(service.verify).to be(true)
-        end
+      it 'sets verified_at to a date' do
+        service.verify(token:)
+        expect(school.reload.verified_at).to be_a(ActiveSupport::TimeWithZone)
       end
 
-      describe 'when school cannot be saved' do
-        let(:website) { 'invalid' }
-
-        it 'does not save the school' do
-          service.verify
-          expect(school).not_to be_persisted
-        end
-
-        it 'returns false' do
-          expect(service.verify).to be(false)
-        end
+      it 'returns true' do
+        expect(service.verify(token:)).to be(true)
       end
     end
 
-    # TODO: Remove these examples once the feature flag is retired
-    describe 'when immediate onboarding is disabled' do
-      around do |example|
-        ClimateControl.modify(ENABLE_IMMEDIATE_SCHOOL_ONBOARDING: nil) do
-          example.run
-        end
-      end
-
-      describe 'when school can be saved' do
-        it 'saves the school' do
-          service.verify(token:)
-          expect(school).to be_persisted
-        end
-
-        it 'sets verified_at to a date' do
-          service.verify(token:)
-          expect(school.reload.verified_at).to be_a(ActiveSupport::TimeWithZone)
-        end
-
-        it 'generates school code' do
-          service.verify(token:)
-          expect(school.reload.code).to be_present
-        end
+    describe 'when school cannot be saved' do
+      let(:website) { 'invalid' }
 
-        it 'grants the creator the owner role for the school' do
-          service.verify(token:)
-          expect(school_creator).to be_school_owner(school)
-        end
-
-        it 'grants the creator the teacher role for the school' do
-          service.verify(token:)
-          expect(school_creator).to be_school_teacher(school)
-        end
-
-        it 'creates the school in Profile API' do
-          service.verify(token:)
-          expect(ProfileApiClient).to have_received(:create_school).with(token:, id: school.id, code: school.code)
-        end
-
-        it 'returns true' do
-          expect(service.verify(token:)).to be(true)
-        end
+      it 'does not save the school' do
+        service.verify(token:)
+        expect(school).not_to be_persisted
       end
 
-      describe 'when school cannot be saved' do
-        let(:website) { 'invalid' }
-
-        it 'does not save the school' do
-          service.verify(token:)
-          expect(school).not_to be_persisted
-        end
-
-        it 'does not create owner role' do
-          service.verify(token:)
-          expect(school_creator).not_to be_school_owner(school)
-        end
-
-        it 'does not create teacher role' do
-          service.verify(token:)
-          expect(school_creator).not_to be_school_teacher(school)
-        end
-
-        it 'does not create school in Profile API' do
-          expect(ProfileApiClient).not_to have_received(:create_school)
-        end
-
-        it 'returns false' do
-          expect(service.verify(token:)).to be(false)
-        end
-      end
-
-      describe 'when the school cannot be created in Profile API' do
-        before do
-          allow(ProfileApiClient).to receive(:create_school).and_raise(RuntimeError)
-        end
-
-        it 'does not save the school' do
-          service.verify(token:)
-          expect { school.reload }.to raise_error(ActiveRecord::RecordNotFound)
-        end
-
-        it 'does not create owner role' do
-          service.verify(token:)
-          expect(school_creator).not_to be_school_owner(school)
-        end
-
-        it 'does not create teacher role' do
-          service.verify(token:)
-          expect(school_creator).not_to be_school_teacher(school)
-        end
-
-        it 'does not create school in Profile API' do
-          expect(ProfileApiClient).not_to have_received(:create_school)
-        end
-
-        it 'returns false' do
-          expect(service.verify(token:)).to be(false)
-        end
-      end
-
-      describe 'when teacher and owner roles cannot be created because they already have a role in another school' do
-        let(:another_school) { create(:school) }
-
-        before do
-          create(:role, user_id: school.creator_id, school: another_school)
-        end
-
-        it 'does not save the school' do
-          service.verify(token:)
-          expect { school.reload }.to raise_error(ActiveRecord::RecordNotFound)
-        end
-
-        it 'does not create owner role' do
-          service.verify(token:)
-          expect(school_creator).not_to be_school_owner(school)
-        end
-
-        it 'does not create teacher role' do
-          service.verify(token:)
-          expect(school_creator).not_to be_school_teacher(school)
-        end
-
-        it 'does not create school in Profile API' do
-          expect(ProfileApiClient).not_to have_received(:create_school)
-        end
-
-        it 'returns false' do
-          expect(service.verify(token:)).to be(false)
-        end
+      it 'returns false' do
+        expect(service.verify(token:)).to be(false)
       end
     end
   end
@@ -202,7 +61,7 @@
 
   describe 'when the school was previously verified' do
     before do
-      service.verify
+      service.verify(token:)
       service.reject
       school.reload
     end