diff --git a/x-pack/plugins/fleet/public/applications/fleet/sections/agent_policy/components/agent_policy_advanced_fields/index.tsx b/x-pack/plugins/fleet/public/applications/fleet/sections/agent_policy/components/agent_policy_advanced_fields/index.tsx
index 28d14b62a575e..9e35dc441fa28 100644
--- a/x-pack/plugins/fleet/public/applications/fleet/sections/agent_policy/components/agent_policy_advanced_fields/index.tsx
+++ b/x-pack/plugins/fleet/public/applications/fleet/sections/agent_policy/components/agent_policy_advanced_fields/index.tsx
@@ -77,9 +77,8 @@ export const AgentPolicyAdvancedOptionsContent: React.FunctionComponent<Props> =
   validation,
   disabled = false,
 }) => {
-  const useSpaceAwareness = ExperimentalFeaturesService.get()?.useSpaceAwareness ?? false;
   const { docLinks } = useStartServices();
-  const { spaceId } = useFleetStatus();
+  const { spaceId, isSpaceAwarenessEnabled } = useFleetStatus();
 
   const { getAbsolutePath } = useLink();
   const AgentTamperProtectionWrapper = useUIExtension(
@@ -263,21 +262,21 @@ export const AgentPolicyAdvancedOptionsContent: React.FunctionComponent<Props> =
           />
         </EuiFormRow>
       </EuiDescribedFormGroup>
-      {useSpaceAwareness ? (
+      {isSpaceAwarenessEnabled ? (
         <EuiDescribedFormGroup
           fullWidth
           title={
             <h3>
               <FormattedMessage
                 id="xpack.fleet.agentPolicyForm.spaceFieldLabel"
-                defaultMessage="Space"
+                defaultMessage="Spaces"
               />
             </h3>
           }
           description={
             <FormattedMessage
               id="xpack.fleet.agentPolicyForm.spaceDescription"
-              defaultMessage="Select a space for this policy or create a new one. {link}"
+              defaultMessage="Select one or more spaces for this policy or create a new one. {link}"
               values={{
                 link: (
                   <EuiLink
@@ -312,6 +311,9 @@ export const AgentPolicyAdvancedOptionsContent: React.FunctionComponent<Props> =
                   : [spaceId || 'default']
               }
               onChange={(newValue) => {
+                if (newValue.length === 0) {
+                  return;
+                }
                 updateAgentPolicy({
                   space_ids: newValue,
                 });
diff --git a/x-pack/plugins/fleet/server/types/models/agent_policy.ts b/x-pack/plugins/fleet/server/types/models/agent_policy.ts
index f977392547400..560f6939eedba 100644
--- a/x-pack/plugins/fleet/server/types/models/agent_policy.ts
+++ b/x-pack/plugins/fleet/server/types/models/agent_policy.ts
@@ -41,11 +41,7 @@ function isInteger(n: number) {
 
 export const AgentPolicyBaseSchema = {
   id: schema.maybe(schema.string()),
-  space_ids: schema.maybe(
-    schema.arrayOf(schema.string(), {
-      minSize: 1,
-    })
-  ),
+  space_ids: schema.maybe(schema.arrayOf(schema.string())),
   name: schema.string({ minLength: 1, validate: validateNonEmptyString }),
   namespace: AgentPolicyNamespaceSchema,
   description: schema.maybe(schema.string()),
diff --git a/x-pack/test/fleet_api_integration/apis/agent_policy/agent_policy.ts b/x-pack/test/fleet_api_integration/apis/agent_policy/agent_policy.ts
index be968e21feb97..80309b8909363 100644
--- a/x-pack/test/fleet_api_integration/apis/agent_policy/agent_policy.ts
+++ b/x-pack/test/fleet_api_integration/apis/agent_policy/agent_policy.ts
@@ -906,6 +906,7 @@ export default function (providerContext: FtrProviderContext) {
     describe('PUT /api/fleet/agent_policies/{agentPolicyId}', () => {
       before(async () => {
         await esArchiver.load('x-pack/test/functional/es_archives/fleet/empty_fleet_server');
+        await kibanaServer.savedObjects.cleanStandardList();
       });
       const createdPolicyIds: string[] = [];
       after(async () => {
@@ -967,6 +968,53 @@ export default function (providerContext: FtrProviderContext) {
         });
       });
 
+      it('should support empty space_ids', async () => {
+        const {
+          body: { item: originalPolicy },
+        } = await supertest
+          .post(`/api/fleet/agent_policies`)
+          .set('kbn-xsrf', 'xxxx')
+          .send({
+            name: 'Initial name 2',
+            space_ids: [],
+            description: 'Initial description',
+            namespace: 'default',
+          })
+          .expect(200);
+        agentPolicyId = originalPolicy.id;
+        const {
+          body: { item: updatedPolicy },
+        } = await supertest
+          .put(`/api/fleet/agent_policies/${agentPolicyId}`)
+          .set('kbn-xsrf', 'xxxx')
+          .send({
+            name: 'Updated name 2',
+            space_ids: [],
+            description: 'Updated description',
+            namespace: 'default',
+            is_protected: false,
+          })
+          .expect(200);
+        createdPolicyIds.push(updatedPolicy.id);
+        // eslint-disable-next-line @typescript-eslint/naming-convention
+        const { id, updated_at, version, ...newPolicy } = updatedPolicy;
+
+        expect(newPolicy).to.eql({
+          status: 'active',
+          name: 'Updated name 2',
+          description: 'Updated description',
+          namespace: 'default',
+          is_managed: false,
+          revision: 2,
+          schema_version: FLEET_AGENT_POLICIES_SCHEMA_VERSION,
+          updated_by: 'elastic',
+          inactivity_timeout: 1209600,
+          package_policies: [],
+          is_protected: false,
+          space_ids: [],
+        });
+      });
+
       it('should return a 409 if policy already exists with name given', async () => {
         const sharedBody = {
           name: 'Initial name',
@@ -1053,7 +1101,7 @@ export default function (providerContext: FtrProviderContext) {
           .put(`/api/fleet/agent_policies/${originalPolicy.id}`)
           .set('kbn-xsrf', 'xxxx')
           .send({
-            name: 'Updated name',
+            name: `Updated name ${Date.now()}`,
             description: 'Initial description',
             namespace: 'default',
           })