diff --git a/app/events/members/approved_invite_event.rb b/app/events/members/approved_invite_event.rb
new file mode 100644
index 0000000000000000000000000000000000000000..e98754b66510a373d2b5ef96434e5ff31d613d22
--- /dev/null
+++ b/app/events/members/approved_invite_event.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Members
+  class ApprovedInviteEvent < ::Gitlab::EventStore::Event
+    def schema
+      {
+        'type' => 'object',
+        'required' => %w[source_id source_type user_ids member_ids],
+        'properties' => {
+          'source_id' => { 'type' => 'integer' },
+          'source_type' => { 'type' => 'string' },
+          'user_ids' => {
+            'type' => 'array',
+            'items' => { 'type' => 'integer' }
+          },
+          'member_ids' => {
+            'type' => 'array',
+            'items' => { 'type' => 'integer' }
+          }
+        }
+      }
+    end
+  end
+end
diff --git a/app/services/members/approve_invite_service.rb b/app/services/members/approve_invite_service.rb
new file mode 100644
index 0000000000000000000000000000000000000000..c3f6dbc1d349c06774460365e79342da61e9b2fd
--- /dev/null
+++ b/app/services/members/approve_invite_service.rb
@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+module Members
+  class ApproveInviteService < Members::BaseService
+    def initialize(...)
+      super
+
+      @member = @params[:member]
+    end
+
+    def execute
+      return unless member
+      return unless user
+
+      return error_email_mismatch unless user.verified_email?(member_email)
+      return error_approval unless member.accept_invite!(user)
+
+      log_approval
+      publish_approval_event
+      success
+    end
+
+    private
+
+    attr_reader :member
+    alias_method :user, :current_user
+
+    def error_email_mismatch
+      log_error(
+        "#{error_email_mismatch_message} Member email address #{member_email} and user email addresses #{user_emails}."
+      )
+      error(error_email_mismatch_message)
+    end
+
+    def error_approval
+      log_error("#{error_approval_message} Member #{member.id} and user #{user.id}.")
+      error(error_approval_message)
+    end
+
+    def log_approval
+      log_info("The invitation to become member #{member.id} was accepted by user #{user.id}.")
+    end
+
+    def publish_approval_event
+      Gitlab::EventStore.publish(
+        Members::ApprovedInviteEvent.new(data: {
+          source_id: member.source_id,
+          source_type: member.source_type,
+          user_ids: [user.id],
+          member_ids: [member.id]
+        })
+      )
+    end
+
+    def member_email
+      member.invite_email
+    end
+
+    def user_emails
+      user.verified_emails.join(', ')
+    end
+
+    def error_email_mismatch_message
+      _("The invitation could not be accepted because the email addresses of the user and invited member don't match.")
+    end
+
+    def error_approval_message
+      _("The invitation could not be accepted.")
+    end
+  end
+end
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index e1e1b2c2aa223e0c56565d822d50eecae25201e4..c3252156d0aa4511df7fb8745cb74f62c61b300a 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -65394,6 +65394,9 @@ msgstr ""
 msgid "The invitation can not be found with the provided invite token."
 msgstr ""
 
+msgid "The invitation could not be accepted because the email addresses of the user and invited member don't match."
+msgstr ""
+
 msgid "The invitation could not be accepted."
 msgstr ""
 
diff --git a/spec/services/members/approve_invite_service_spec.rb b/spec/services/members/approve_invite_service_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..ea5c85980f84085bbbf6b6087f48674804a7ed14
--- /dev/null
+++ b/spec/services/members/approve_invite_service_spec.rb
@@ -0,0 +1,110 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Members::ApproveInviteService, :aggregate_failures, :clean_gitlab_redis_shared_state, :sidekiq_inline,
+  feature_category: :groups_and_projects do
+  let(:user) { create(:user, email: 'user1@example.com') }
+  let(:member) { create(:project_member, :invited, invite_email: user.email) }
+  let(:service) { described_class.new(user, member: member) }
+  let(:error_email_mismatch_message) do
+    "The invitation could not be accepted because the email addresses of the user and invited member don't match."
+  end
+
+  subject(:result) { service.execute }
+
+  describe '#execute' do
+    context 'when member is nil' do
+      let(:service) { described_class.new(user, member: nil) }
+
+      it 'returns nil without processing' do
+        expect(result).to be_nil
+      end
+    end
+
+    context 'when user is nil' do
+      let(:service) { described_class.new(nil, member: member) }
+
+      it 'returns nil without processing' do
+        expect(result).to be_nil
+      end
+    end
+
+    context 'when user email does not match member invite email' do
+      let(:member) { create(:project_member, :invited, invite_email: 'user2@example.com') }
+
+      it 'returns an error response' do
+        expect(result[:status]).to eq(:error)
+        expect(result[:message]).to eq(error_email_mismatch_message)
+      end
+
+      it 'logs the email mismatch error' do
+        error = error_email_mismatch_message
+        user_email1 = 'user1@example.com'
+        user_email2 = Gitlab::PrivateCommitEmail.for_user(user)
+        member_email = 'user2@example.com'
+        log = "#{error} Member email address #{member_email} and user email addresses #{user_email1}, #{user_email2}."
+
+        expect(service).to receive(:log_error).with(log)
+        result
+      end
+
+      it 'does not accept the invitation' do
+        expect { result }.not_to change { member.user }
+      end
+    end
+
+    context 'when member fails to accept invitation' do
+      before do
+        allow(member).to receive(:accept_invite!).with(user).and_return(false)
+      end
+
+      it 'returns an error response' do
+        expect(result[:status]).to eq(:error)
+        expect(result[:message]).to eq('The invitation could not be accepted.')
+      end
+
+      it 'logs the approval error' do
+        expect(service).to receive(:log_error).with(
+          "The invitation could not be accepted. Member #{member.id} and user #{user.id}."
+        )
+        result
+      end
+
+      it 'does not accept the invitation' do
+        expect { result }.not_to change { member.user }
+      end
+    end
+
+    context 'when invitation is accepted' do
+      it 'returns a success response' do
+        expect(result[:status]).to eq :success
+      end
+
+      it 'accepts the invitation' do
+        expect { result }.to change { member.user }.from(nil).to(user)
+      end
+
+      it 'logs the successful approval' do
+        expect(service).to receive(:log_info).with(
+          "The invitation to become member #{member.id} was accepted by user #{user.id}."
+        )
+        result
+      end
+
+      it 'publishes the approval event' do
+        expect(Gitlab::EventStore).to receive(:publish) do |event|
+          expect(event).to be_an_instance_of(Members::ApprovedInviteEvent)
+          expect(event.data).to eq({
+            "source_id" => member.source_id,
+            "source_type" => 'Project',
+            "user_ids" => [user.id],
+            "member_ids" => [member.id]
+          })
+        end
+
+        result
+      end
+    end
+  end
+end