diff --git a/app/services/gpo_reminder_sender.rb b/app/services/gpo_reminder_sender.rb
index 32dcf07a20d..867cbd77130 100644
--- a/app/services/gpo_reminder_sender.rb
+++ b/app/services/gpo_reminder_sender.rb
@@ -7,7 +7,12 @@ def send_emails(for_letters_sent_before)
 
     profiles_due_for_reminder(letter_eligible_range).each do |profile|
       profile.user.send_email_to_all_addresses(:gpo_reminder)
-      profile.gpo_confirmation_codes.first.update(reminder_sent_at: Time.zone.now)
+      profile.gpo_confirmation_codes.all.each do |gpo_code|
+        next if gpo_code.reminder_sent_at
+        next unless letter_eligible_range.cover?(gpo_code.created_at)
+
+        gpo_code.update(reminder_sent_at: Time.zone.now)
+      end
       analytics.idv_gpo_reminder_email_sent(user_id: profile.user.uuid)
     end
   end
diff --git a/spec/services/gpo_reminder_sender_spec.rb b/spec/services/gpo_reminder_sender_spec.rb
index 4d8fbd89d28..4b8f866842d 100644
--- a/spec/services/gpo_reminder_sender_spec.rb
+++ b/spec/services/gpo_reminder_sender_spec.rb
@@ -54,11 +54,19 @@ def set_gpo_verification_pending_at(user, to_time)
       user.
         gpo_verification_pending_profile.
         update(gpo_verification_pending_at: to_time)
+
+      user.
+        gpo_verification_pending_profile.
+        gpo_confirmation_codes.each do |code|
+          code.update(code_sent_at: to_time, created_at: to_time, updated_at: to_time)
+        end
     end
 
     def set_reminder_sent_at(to_time)
       gpo_confirmation_code.update(
         reminder_sent_at: to_time,
+        created_at: to_time,
+        updated_at: to_time,
       )
     end
 
@@ -72,17 +80,22 @@ def set_reminder_sent_at(to_time)
 
     context 'when a user has requested two letters' do
       before do
-        set_gpo_verification_pending_at(user, time_due_for_reminder - 2.days)
-        new_confirmation_code = create(:gpo_confirmation_code)
+        timestamp = time_due_for_reminder - 2.days
+        set_gpo_verification_pending_at(user, timestamp)
+        new_confirmation_code = create(:gpo_confirmation_code, created_at: timestamp)
         user.gpo_verification_pending_profile.gpo_confirmation_codes << new_confirmation_code
       end
 
       include_examples 'sends emails', expected_number_of_emails: 2
 
-      it 'updates the GPO verification code `reminder_sent_at`' do
+      it 'updates the GPO verification code `reminder_sent_at` for both codes' do
         subject.send_emails(time_due_for_reminder)
+        user.gpo_verification_pending_profile.gpo_confirmation_codes.each(&:reload)
 
-        expect(gpo_confirmation_code.reminder_sent_at).to be_within(1.second).of(Time.zone.now)
+        expect(user.gpo_verification_pending_profile.gpo_confirmation_codes[0].reminder_sent_at).
+          to be_within(1.second).of(Time.zone.now)
+        expect(user.gpo_verification_pending_profile.gpo_confirmation_codes[1].reminder_sent_at).
+          to be_within(1.second).of(Time.zone.now)
       end
     end
 
@@ -93,6 +106,7 @@ def set_reminder_sent_at(to_time)
 
       it 'updates the GPO verification code `reminder_sent_at`' do
         subject.send_emails(time_due_for_reminder)
+        gpo_confirmation_code.reload
 
         expect(gpo_confirmation_code.reminder_sent_at).to be_within(1.second).of(Time.zone.now)
       end
@@ -106,6 +120,7 @@ def set_reminder_sent_at(to_time)
 
         it 'updates the GPO verification code `reminder_sent_at`' do
           subject.send_emails(time_due_for_reminder)
+          gpo_confirmation_code.reload
 
           expect(gpo_confirmation_code.reminder_sent_at).to be_within(1.second).of(Time.zone.now)
         end