diff --git a/robottelo/cli/activationkey.py b/robottelo/cli/activationkey.py
index 8a58b2f7bb2..521c1d46674 100644
--- a/robottelo/cli/activationkey.py
+++ b/robottelo/cli/activationkey.py
@@ -40,12 +40,6 @@ def add_host_collection(cls, options=None):
         cls.command_sub = 'add-host-collection'
         return cls.execute(cls._construct_command(options))
 
-    @classmethod
-    def add_subscription(cls, options=None):
-        """Add subscription"""
-        cls.command_sub = 'add-subscription'
-        return cls.execute(cls._construct_command(options))
-
     @classmethod
     def content_override(cls, options=None):
         """Override product content defaults"""
@@ -81,15 +75,3 @@ def remove_repository(cls, options=None):
         """Disassociate a resource"""
         cls.command_sub = 'remove-repository'
         return cls.execute(cls._construct_command(options))
-
-    @classmethod
-    def remove_subscription(cls, options=None):
-        """Remove subscription"""
-        cls.command_sub = 'remove-subscription'
-        return cls.execute(cls._construct_command(options))
-
-    @classmethod
-    def subscriptions(cls, options=None, output_format=None):
-        """List associated subscriptions"""
-        cls.command_sub = 'subscriptions'
-        return cls.execute(cls._construct_command(options), output_format=output_format)
diff --git a/robottelo/cli/host.py b/robottelo/cli/host.py
index e82f89af49c..ac5ddb506b4 100644
--- a/robottelo/cli/host.py
+++ b/robottelo/cli/host.py
@@ -407,45 +407,6 @@ def subscription_unregister(cls, options=None):
         cls.command_sub = 'subscription unregister'
         return cls.execute(cls._construct_command(options))
 
-    @classmethod
-    def subscription_attach(cls, options=None):
-        """Attach a subscription to host
-
-        Usage::
-
-            hammer host subscription attach [OPTIONS]
-
-        Options::
-
-            --host HOST_NAME                  Name to search by
-            --host-id HOST_ID                 Host ID
-            --quantity Quantity               Quantity of this subscriptions to
-                                              add. Defaults to 1
-            --subscription-id SUBSCRIPTION_ID ID of subscription
-        """
-        cls.command_sub = 'subscription attach'
-        return cls.execute(cls._construct_command(options))
-
-    @classmethod
-    def subscription_remove(cls, options=None):
-        """Remove a subscription from host
-
-        Usage::
-
-            hammer host subscription remove [OPTIONS]
-
-        Options::
-
-            --host HOST_NAME                    Name to search by
-            --host-id HOST_ID
-            --quantity Quantity                 Remove the first instance of a
-                                                subscription with matching id
-                                                and quantity
-            --subscription-id SUBSCRIPTION_ID   ID of subscription
-        """
-        cls.command_sub = 'subscription remove'
-        return cls.execute(cls._construct_command(options))
-
     @classmethod
     def sc_params(cls, options=None):
         """List all smart class parameters
diff --git a/robottelo/host_helpers/cli_factory.py b/robottelo/host_helpers/cli_factory.py
index 637de8cb926..a477724f044 100644
--- a/robottelo/host_helpers/cli_factory.py
+++ b/robottelo/host_helpers/cli_factory.py
@@ -546,34 +546,6 @@ def make_template(self, options=None):
 
         return create_object(self._satellite.cli.Template, args, options)
 
-    def activationkey_add_subscription_to_repo(self, options=None):
-        """Helper function that adds subscription to an activation key"""
-        # List the subscriptions in given org
-        subscriptions = self._satellite.cli.Subscription.list(
-            {'organization-id': options['organization-id']}, per_page=False
-        )
-        # Add subscription to activation-key
-        if options['subscription'] not in (sub['name'] for sub in subscriptions):
-            raise CLIFactoryError(
-                'Subscription {} not found in the given org'.format(options['subscription'])
-            )
-        for subscription in subscriptions:
-            if subscription['name'] == options['subscription']:
-                if subscription['quantity'] != 'Unlimited' and int(subscription['quantity']) == 0:
-                    raise CLIFactoryError('All the subscriptions are already consumed')
-                try:
-                    self._satellite.cli.ActivationKey.add_subscription(
-                        {
-                            'id': options['activationkey-id'],
-                            'subscription-id': subscription['id'],
-                            'quantity': 1,
-                        }
-                    )
-                except CLIReturnCodeError as err:
-                    raise CLIFactoryError(
-                        f'Failed to add subscription to activation key\n{err.msg}'
-                    ) from err
-
     def override_repos_for_activation_key(self, ak_id, repos, value=True):
         """Hammer override satellite repo(s) to value for Activation Key.
 
@@ -722,15 +694,6 @@ def setup_org_for_a_custom_repo(self, options=None):
                     f'Failed to associate activation-key with CV\n{err.msg}'
                 ) from err
 
-        # Add custom_product subscription to activation-key, if SCA mode is disabled
-        if self._satellite.is_sca_mode_enabled(org_id) is False:
-            self.activationkey_add_subscription_to_repo(
-                {
-                    'activationkey-id': activationkey_id,
-                    'organization-id': org_id,
-                    'subscription': custom_product['name'],
-                }
-            )
         # Override custom product to true ( turned off by default in 6.14 )
         custom_repo = self._satellite.cli.Repository.info({'id': custom_repo['id']})
         self._satellite.cli.ActivationKey.content_override(
@@ -874,17 +837,6 @@ def _setup_org_for_a_rh_repo(self, options=None, force=False):
                     f'Failed to associate activation-key with CV\n{err.msg}'
                 ) from err
 
-        # Add default subscription to activation-key, if SCA mode is disabled
-        if self._satellite.is_sca_mode_enabled(org_id) is False:
-            self.activationkey_add_subscription_to_repo(
-                {
-                    'organization-id': org_id,
-                    'activationkey-id': activationkey_id,
-                    'subscription': options.get(
-                        'subscription', constants.DEFAULT_SUBSCRIPTION_NAME
-                    ),
-                }
-            )
         # Override RHST product to true ( turned off by default in 6.14 )
         rhel_repo = self._satellite.cli.Repository.info({'id': rhel_repo['id']})
         self._satellite.cli.ActivationKey.content_override(
@@ -1058,7 +1010,6 @@ def setup_cdn_and_custom_repos_content(
         lce_id=None,
         repos=None,
         download_policy='on_demand',
-        rh_subscriptions=None,
         default_cv=False,
     ):
         """Setup cdn and custom repositories, content view and activations key
@@ -1069,14 +1020,10 @@ def setup_cdn_and_custom_repos_content(
         :param bool default_cv: whether to use the Default Organization CV
         :param str download_policy: update the repositories with this download
             policy
-        :param list rh_subscriptions: a list of RH subscription to attach to
-            activation key
         :return: a dict containing the activation key, content view and repos info
         """
         if repos is None:
             repos = []
-        if rh_subscriptions is None:
-            rh_subscriptions = []
 
         custom_product, repos_info = self.setup_cdn_and_custom_repositories(
             org_id=org_id, repos=repos, download_policy=download_policy
diff --git a/robottelo/host_helpers/repository_mixins.py b/robottelo/host_helpers/repository_mixins.py
index 5d99fe0b6aa..dfee89e8aa1 100644
--- a/robottelo/host_helpers/repository_mixins.py
+++ b/robottelo/host_helpers/repository_mixins.py
@@ -716,34 +716,6 @@ def setup_activation_key(
                         'value': int(override),
                     }
                 )
-        if self.satellite.is_sca_mode_enabled(org_id):
-            return activation_key
-        # Add subscriptions to activation-key
-        # Get organization subscriptions
-        subscriptions = self.satellite.cli.Subscription.list(
-            {'organization-id': org_id}, per_page=False
-        )
-        added_subscription_names = []
-        for subscription in subscriptions:
-            if (
-                subscription['name'] in subscription_names
-                and subscription['name'] not in added_subscription_names
-            ):
-                self.satellite.cli.ActivationKey.add_subscription(
-                    {
-                        'id': activation_key['id'],
-                        'subscription-id': subscription['id'],
-                        'quantity': 1,
-                    }
-                )
-                added_subscription_names.append(subscription['name'])
-                if len(added_subscription_names) == len(subscription_names):
-                    break
-        missing_subscription_names = set(subscription_names).difference(
-            set(added_subscription_names)
-        )
-        if missing_subscription_names:
-            raise ValueError(f'Missing subscriptions: {missing_subscription_names}')
         return activation_key
 
     def organization_has_manifest(self, organization_id):
@@ -760,7 +732,6 @@ def setup_content(
         org_id,
         lce_id,
         download_policy='on_demand',
-        rh_subscriptions=None,
         override=None,
     ):
         """
@@ -769,34 +740,15 @@ def setup_content(
         :param org_id: The organization id
         :param lce_id: The lifecycle environment id
         :param download_policy: The repositories download policy
-        :param rh_subscriptions: The RH subscriptions to be added to activation key
         :param override: Content override (True = enable, False = disable, None = no action)
         """
         if self._repos_info:
             raise RepositoryAlreadyCreated('Repositories already created can not setup content')
-        if rh_subscriptions is None:
-            rh_subscriptions = []
-        if self.need_subscription and not rh_subscriptions:
-            # add the default subscription if no subscription provided
-            rh_subscriptions = [constants.DEFAULT_SUBSCRIPTION_NAME]
         custom_product, repos_info = self.setup(org_id=org_id, download_policy=download_policy)
         content_view, lce = self.setup_content_view(org_id, lce_id)
-        custom_product_name = custom_product['name'] if custom_product else None
-        subscription_names = list(rh_subscriptions)
-        if custom_product_name:
-            subscription_names.append(custom_product_name)
-        if not self.satellite.is_sca_mode_enabled(org_id):
-            activation_key = self.setup_activation_key(
-                org_id,
-                content_view['id'],
-                lce_id,
-                subscription_names=subscription_names,
-                override=override,
-            )
-        else:
-            activation_key = self.setup_activation_key(
-                org_id, content_view['id'], lce_id, override=override
-            )
+        activation_key = self.setup_activation_key(
+            org_id, content_view['id'], lce_id, override=override
+        )
         setup_content_data = dict(
             activation_key=activation_key,
             content_view=content_view,
diff --git a/robottelo/hosts.py b/robottelo/hosts.py
index 33bed747cf2..3d3137d302f 100644
--- a/robottelo/hosts.py
+++ b/robottelo/hosts.py
@@ -1344,7 +1344,6 @@ def virt_who_hypervisor_config(
             org['id'],
             lce['id'],
             repos,
-            rh_subscriptions=[constants.DEFAULT_SUBSCRIPTION_NAME],
         )
         activation_key = content_setup_data['activation_key']
         content_view = content_setup_data['content_view']
@@ -1447,20 +1446,8 @@ def virt_who_hypervisor_config(
         if len(org_hosts) == 0:
             raise CLIFactoryError(f'Failed to find hypervisor host:\n{result.stderr}')
         virt_who_hypervisor_host = org_hosts[0]
-        subscription_id = None
-        if hypervisor_hostname and subscription_name:
-            subscriptions = satellite.cli.Subscription.list(
-                {'organization-id': org_id}, per_page=False
-            )
-            for subscription in subscriptions:
-                if subscription['name'] == subscription_name:
-                    subscription_id = subscription['id']
-                    Host.subscription_attach(
-                        {'host': virt_who_hypervisor_hostname, 'subscription-id': subscription_id}
-                    )
-                    break
         return {
-            'subscription_id': subscription_id,
+            'subscription_id': None,
             'subscription_name': subscription_name,
             'activation_key_id': activation_key['id'],
             'organization_id': org['id'],
@@ -2481,22 +2468,8 @@ def register_host_custom_repo(self, module_org, rhel_contenthost, repo_urls):
         rhsm_id = rhel_contenthost.execute('subscription-manager identity')
         assert module_org.name in rhsm_id.stdout, 'Host is not registered to expected organization'
         rhel_contenthost._satellite = self
-
-        # Attach product subscriptions to contenthost, only if SCA mode is disabled
-        if self.is_sca_mode_enabled(module_org.id) is False:
-            subs = self.api.Subscription(organization=module_org, name=prod.name).search()
-            assert len(subs), f'Subscription for sat client product: {prod.name} was not found.'
-            subscription = subs[0]
-
-            rhel_contenthost.nailgun_host.bulk_add_subscriptions(
-                data={
-                    "organization_id": module_org.id,
-                    "included": {"ids": [rhel_contenthost.nailgun_host.id]},
-                    "subscriptions": [{"id": subscription.id, "quantity": 1}],
-                }
-            )
-            # refresh repository metadata on the host
-            rhel_contenthost.execute('subscription-manager repos --list')
+        # refresh repository metadata on the host
+        rhel_contenthost.execute('subscription-manager repos --list')
 
         # Override the repos to enabled
         rhel_contenthost.execute(r'subscription-manager repos --enable \*')
diff --git a/tests/foreman/api/test_subscription.py b/tests/foreman/api/test_subscription.py
index efcc363e864..f6dc299bb5b 100644
--- a/tests/foreman/api/test_subscription.py
+++ b/tests/foreman/api/test_subscription.py
@@ -23,11 +23,9 @@
 from nailgun.config import ServerConfig
 from nailgun.entity_mixins import TaskFailedError
 import pytest
-from requests.exceptions import HTTPError
 
 from robottelo.config import settings
 from robottelo.constants import (
-    DEFAULT_SUBSCRIPTION_NAME,
     FAKE_0_CUSTOM_PACKAGE_NAME,
     PRDS,
     REPOS,
@@ -226,19 +224,6 @@ def test_sca_end_to_end(
     )
     assert result.status == 0, f'Failed to register host: {result.stderr}'
     assert rhel_contenthost.subscribed
-    # Verify that you cannot attach a subscription to an activation key in SCA Mode
-    subscription = target_sat.api.Subscription(organization=module_sca_manifest_org).search(
-        query={'search': f'name="{DEFAULT_SUBSCRIPTION_NAME}"'}
-    )[0]
-    with pytest.raises(HTTPError) as ak_context:
-        module_ak.add_subscriptions(data={'quantity': 1, 'subscription_id': subscription.id})
-    assert 'Simple Content Access' in ak_context.value.response.text
-    # Verify that you cannot attach a subscription to an Host in SCA Mode
-    with pytest.raises(HTTPError) as host_context:
-        target_sat.api.HostSubscription(host=rhel_contenthost.nailgun_host.id).add_subscriptions(
-            data={'subscriptions': [{'id': subscription.id, 'quantity': 1}]}
-        )
-    assert 'Simple Content Access' in host_context.value.response.text
     # Create a content view with repos and check to see that the client has access
     content_view = target_sat.api.ContentView(organization=module_sca_manifest_org).create()
     content_view.repository = [rh_repo, custom_repo]
diff --git a/tests/foreman/cli/test_activationkey.py b/tests/foreman/cli/test_activationkey.py
index 44dcb7b222b..2ac8703a8d3 100644
--- a/tests/foreman/cli/test_activationkey.py
+++ b/tests/foreman/cli/test_activationkey.py
@@ -1672,15 +1672,3 @@ def test_syspurpose_end_to_end(
     assert host['subscription-information']['system-purpose']['purpose-role'] == "test-role2"
     assert host['subscription-information']['system-purpose']['purpose-usage'] == "test-usage2"
     assert host['subscription-information']['system-purpose']['service-level'] == "Self-Support2"
-
-    rhel_contenthost.unregister()
-    with pytest.raises(CLIReturnCodeError):
-        # raise error that the host was not registered by
-        # subscription-manager register
-        target_sat.cli.ActivationKey.subscriptions(
-            {
-                'organization-id': module_org.id,
-                'id': activation_key.id,
-                'host-id': host['id'],
-            }
-        )
diff --git a/tests/foreman/cli/test_host.py b/tests/foreman/cli/test_host.py
index ffef65fa489..b46c1f4f700 100644
--- a/tests/foreman/cli/test_host.py
+++ b/tests/foreman/cli/test_host.py
@@ -1847,17 +1847,6 @@ def test_positive_register(
     assert len(hosts) > 0
     host = target_sat.cli.Host.info({'id': hosts[0]['id']})
     assert host['name'] == rhel_contenthost.hostname
-    # note: when not registered the following command lead to exception,
-    # see unregister
-    host_subscriptions = target_sat.cli.ActivationKey.subscriptions(
-        {
-            'organization-id': module_org.id,
-            'id': module_ak_with_cv.id,
-            'host-id': host['id'],
-        },
-        output_format='json',
-    )
-    assert len(host_subscriptions) == 0
 
 
 # -------------------------- MULTI-CV SCENARIOS -------------------------
diff --git a/tests/foreman/cli/test_rhcloud_iop.py b/tests/foreman/cli/test_rhcloud_iop.py
index 662bc48f5db..09b0d6f919f 100644
--- a/tests/foreman/cli/test_rhcloud_iop.py
+++ b/tests/foreman/cli/test_rhcloud_iop.py
@@ -149,7 +149,6 @@ def test_positive_install_iop_custom_certs(
         service_level='Self-Support',
         purpose_usage='test-usage',
         purpose_role='test-role',
-        auto_attach=False,
     ).create()
 
     host.configure_rex(satellite=satellite, org=org, register=False)
@@ -198,7 +197,6 @@ def test_disable_enable_iop(satellite_iop, module_sca_manifest, rhel_contenthost
         service_level='Self-Support',
         purpose_usage='test-usage',
         purpose_role='test-role',
-        auto_attach=False,
     ).create()
 
     host.configure_rex(satellite=satellite, org=org, register=False)
diff --git a/tests/foreman/cli/test_subscription.py b/tests/foreman/cli/test_subscription.py
index ba155cae68b..b103d9e46a4 100644
--- a/tests/foreman/cli/test_subscription.py
+++ b/tests/foreman/cli/test_subscription.py
@@ -201,32 +201,6 @@ def test_positive_subscription_status_disabled_golden_ticket():
     """
 
 
-@pytest.mark.stubbed
-def test_positive_candlepin_events_processed_by_STOMP():
-    """Verify that Candlepin events are being read and processed by
-       attaching subscriptions, validating host subscriptions status,
-       and viewing processed and failed Candlepin events
-
-    :id: d54a7652-f87d-4277-a0ec-a153e27b4487
-
-    :steps:
-
-        1. Register Content Host without subscriptions attached
-        2. Verify subscriptions status is invalid
-        3. Import a Manifest
-        4. Attach subs to content host
-        5. Verify subscription status is green, "valid", with
-           "hammer subscription list --host-id x"
-        6. Check for processed and failed Candlepin events
-
-    :expectedresults: Candlepin events are being read and processed
-                      correctly without any failures
-    :BZ: 1826515
-
-    :CaseImportance: High
-    """
-
-
 def test_negative_check_katello_reimport(request, target_sat, function_org):
     """Verify katello:reimport trace should not fail with an TypeError
 
diff --git a/tests/foreman/endtoend/test_api_endtoend.py b/tests/foreman/endtoend/test_api_endtoend.py
index 42818aaec18..03a90ab4b77 100644
--- a/tests/foreman/endtoend/test_api_endtoend.py
+++ b/tests/foreman/endtoend/test_api_endtoend.py
@@ -37,13 +37,11 @@
         '/katello/api/activation_keys/:id',
         '/katello/api/activation_keys/:id',
         '/katello/api/activation_keys/:id',
-        '/katello/api/activation_keys/:id/add_subscriptions',
         '/katello/api/activation_keys/:id/content_override',
         '/katello/api/activation_keys/:id/copy',
         '/katello/api/activation_keys/:id/host_collections/available',
         '/katello/api/activation_keys/:id/product_content',
         '/katello/api/activation_keys/:id/releases',
-        '/katello/api/activation_keys/:id/remove_subscriptions',
     ),
     'advisor_engine': (
         '/api/advisor_engine/host_details',
@@ -424,8 +422,6 @@
     'host_subscriptions': (
         '/api/hosts/:host_id/subscriptions',
         '/api/hosts/:host_id/subscriptions',
-        '/api/hosts/:host_id/subscriptions/add_subscriptions',
-        '/api/hosts/:host_id/subscriptions/remove_subscriptions',
         '/api/hosts/:host_id/subscriptions/available_release_versions',
         '/api/hosts/:host_id/subscriptions/enabled_repositories',
         '/api/hosts/:host_id/subscriptions/content_override',
@@ -489,8 +485,6 @@
         '/api/hosts/bulk/assign_location',
         '/api/hosts/bulk/add_host_collections',
         '/api/hosts/bulk/remove_host_collections',
-        '/api/hosts/bulk/add_subscriptions',
-        '/api/hosts/bulk/remove_subscriptions',
         '/api/hosts/bulk/applicable_errata',
         '/api/hosts/bulk/installable_errata',
         '/api/hosts/bulk/available_incremental_updates',
diff --git a/tests/new_upgrades/test_errata.py b/tests/new_upgrades/test_errata.py
index f642d348d94..10db61c4b93 100644
--- a/tests/new_upgrades/test_errata.py
+++ b/tests/new_upgrades/test_errata.py
@@ -164,11 +164,6 @@ def generate_errata_for_client_setup(
             environment=environment,
         ).create()
         test_data.activation_key = ak.name
-        if not target_sat.is_sca_mode_enabled(org.id):
-            subscription = target_sat.api.Subscription(organization=org).search(
-                query={'search': f'name={product.name}'}
-            )[0]
-            ak.add_subscriptions(data={'subscription_id': subscription.id})
         # Override/enable all AK repos (disabled by default since 6.15)
         c_labels = [
             i['label'] for i in ak.product_content(data={'content_access_mode_all': '1'})['results']
diff --git a/tests/new_upgrades/test_repository.py b/tests/new_upgrades/test_repository.py
index 38c5d2ec637..73fc2b2207d 100644
--- a/tests/new_upgrades/test_repository.py
+++ b/tests/new_upgrades/test_repository.py
@@ -79,11 +79,6 @@ def custom_repo_check_setup(sat_upgrade_chost, content_upgrade_shared_satellite,
         ak = target_sat.api.ActivationKey(
             content_view=content_view, organization=org.id, environment=lce, name=test_name
         ).create()
-        if not target_sat.is_sca_mode_enabled(org.id):
-            subscription = target_sat.api.Subscription(organization=org).search(
-                query={'search': f'name={product.name}'}
-            )[0]
-            ak.add_subscriptions(data={'subscription_id': subscription.id})
         sat_upgrade_chost.api_register(
             target_sat, organization=org, activation_keys=[ak.name], location=None
         )
diff --git a/tests/upgrades/test_errata.py b/tests/upgrades/test_errata.py
index f151dc0c504..5c96ba557a6 100644
--- a/tests/upgrades/test_errata.py
+++ b/tests/upgrades/test_errata.py
@@ -150,11 +150,6 @@ def test_pre_scenario_generate_errata_for_client(
         ak = target_sat.api.ActivationKey(
             content_view=content_view, organization=function_org, environment=environment
         ).create()
-        if not target_sat.is_sca_mode_enabled(function_org.id):
-            subscription = target_sat.api.Subscription(organization=function_org).search(
-                query={'search': f'name={product.name}'}
-            )[0]
-            ak.add_subscriptions(data={'subscription_id': subscription.id})
         # Override/enable all AK repos (disabled by default since 6.15)
         c_labels = [
             i['label'] for i in ak.product_content(data={'content_access_mode_all': '1'})['results']
diff --git a/tests/upgrades/test_repository.py b/tests/upgrades/test_repository.py
index d1d92daf749..a8139ba8be5 100644
--- a/tests/upgrades/test_repository.py
+++ b/tests/upgrades/test_repository.py
@@ -145,11 +145,6 @@ def test_pre_scenario_custom_repo_check(self, target_sat, sat_upgrade_chost, sav
         ak = target_sat.api.ActivationKey(
             content_view=content_view, organization=org.id, environment=lce
         ).create()
-        if not target_sat.is_sca_mode_enabled(org.id):
-            subscription = target_sat.api.Subscription(organization=org).search(
-                query={'search': f'name={product.name}'}
-            )[0]
-            ak.add_subscriptions(data={'subscription_id': subscription.id})
         # Override/enable all AK repos (disabled by default since 6.15)
         c_labels = [
             i['label'] for i in ak.product_content(data={'content_access_mode_all': '1'})['results']