diff --git a/.changeset/deploy-create-update-feedback.md b/.changeset/deploy-create-update-feedback.md
new file mode 100644
index 000000000..eb75f540c
--- /dev/null
+++ b/.changeset/deploy-create-update-feedback.md
@@ -0,0 +1,5 @@
+---
+'@sanity/cli': minor
+---
+
+feat(deploy): report whether a deploy created a new application or updated an existing one (in the success output and via `target.action` in the dry-run/`--json` payload), and warn that redeploying without `deployment.appId` creates another application
diff --git a/packages/@sanity/cli/src/actions/deploy/__tests__/deployApp.test.ts b/packages/@sanity/cli/src/actions/deploy/__tests__/deployApp.test.ts
index 142cbe99c..502561c15 100644
--- a/packages/@sanity/cli/src/actions/deploy/__tests__/deployApp.test.ts
+++ b/packages/@sanity/cli/src/actions/deploy/__tests__/deployApp.test.ts
@@ -6,12 +6,13 @@ import {logAppDeployed} from '../deployApp.js'
 const mockOutput = () => ({log: vi.fn()}) as unknown as Output
 
 describe('logAppDeployed', () => {
-  test("prints the dashboard URL from the deployed app's organization", () => {
+  test("updating prints the dashboard URL from the deployed app's organization", () => {
     const output = mockOutput()
 
     logAppDeployed({
       applicationId: 'app-1',
       cliConfig: {app: {organizationId: 'config-org'}, deployment: {appId: 'app-1'}} as CliConfig,
+      created: false,
       organizationId: 'org-1',
       output,
       title: 'My App',
@@ -20,6 +21,30 @@ describe('logAppDeployed', () => {
     expect(output.log).toHaveBeenCalledWith(
       expect.stringContaining('Success! Application deployed to'),
     )
+    expect(output.log).toHaveBeenCalledWith(
+      expect.stringContaining('Updated the existing application.'),
+    )
     expect(output.log).toHaveBeenCalledWith(expect.stringContaining('/@org-1/application/app-1'))
   })
+
+  test('creating without an appId warns that a redeploy creates another application', () => {
+    const output = mockOutput()
+
+    logAppDeployed({
+      applicationId: 'app-2',
+      cliConfig: {app: {organizationId: 'org-1'}} as CliConfig,
+      created: true,
+      organizationId: 'org-1',
+      output,
+      title: 'New App',
+    })
+
+    const logged = vi
+      .mocked(output.log)
+      .mock.calls.map((call) => call[0])
+      .join('\n')
+    expect(logged).toContain('Created a new application.')
+    expect(logged).toContain('creates another new application')
+    expect(logged).toContain("appId: 'app-2'")
+  })
 })
diff --git a/packages/@sanity/cli/src/actions/deploy/__tests__/deployChecks.test.ts b/packages/@sanity/cli/src/actions/deploy/__tests__/deployChecks.test.ts
index 6a44e281f..5879f235f 100644
--- a/packages/@sanity/cli/src/actions/deploy/__tests__/deployChecks.test.ts
+++ b/packages/@sanity/cli/src/actions/deploy/__tests__/deployChecks.test.ts
@@ -159,6 +159,7 @@ describe('checkStudioTarget', () => {
     )
     // The URL the human report shows is the same one the JSON reporter reads
     expect(reporter.results[0]?.target).toEqual({
+      action: 'update',
       applicationId: 'app-1',
       title: null,
       url: 'https://my-studio.sanity.studio',
@@ -186,6 +187,7 @@ describe('checkStudioTarget', () => {
     expect(reporter.results[0]?.message).toContain('titled "My Studio"')
     // The JSON target echoes the requested title, matching the human message
     expect(reporter.results[0]?.target).toEqual({
+      action: 'create',
       applicationId: null,
       title: 'My Studio',
       url: 'https://new-studio.sanity.studio',
@@ -300,6 +302,7 @@ describe('checkAppTarget', () => {
     expect(reporter.results[0]).toMatchObject({status: 'pass'})
     expect(reporter.results[0]?.message).toContain('Deploys to existing application "My App"')
     expect(reporter.results[0]?.message).toContain('/@org-1/application/core-1')
+    expect(reporter.results[0]?.target?.action).toBe('update')
     expect(reporter.results[0]?.target?.applicationId).toBe('core-1')
     expect(reporter.results[0]?.target?.url).toContain('/@org-1/application/core-1')
   })
@@ -325,7 +328,12 @@ describe('checkAppTarget', () => {
     expect(reporter.results[0]).toMatchObject({status: 'pass'})
     expect(reporter.results[0]?.message).toContain('Would create a new application "My App"')
     // The JSON target carries the pending title; id and URL come on creation
-    expect(reporter.results[0]?.target).toEqual({applicationId: null, title: 'My App', url: null})
+    expect(reporter.results[0]?.target).toEqual({
+      action: 'create',
+      applicationId: null,
+      title: 'My App',
+      url: null,
+    })
   })
 
   test('needs-input → fail check (would prompt)', async () => {
@@ -386,6 +394,7 @@ describe('checkAppTarget (workbench backend)', () => {
 
     expect(reporter.results[0]).toMatchObject({status: 'pass'})
     expect(reporter.results[0]?.message).toContain('Deploys to existing application "Drop Desk"')
+    expect(reporter.results[0]?.target?.action).toBe('update')
   })
 
   test('unknown appId → fail check pointing to deployment.appId', async () => {
@@ -422,6 +431,7 @@ describe('checkAppTarget (workbench backend)', () => {
       'Would create a new application "New App" with slug "drop-desk"',
     )
     expect(reporter.results[0]?.target).toEqual({
+      action: 'create',
       applicationId: null,
       slug: 'drop-desk',
       title: 'New App',
@@ -445,6 +455,7 @@ describe('checkStudioTarget (workbench backend)', () => {
     expect(reporter.results[0]?.message).toContain(
       'Deploys to existing studio https://my-studio.sanity.studio',
     )
+    expect(target?.action).toBe('update')
     expect(target?.url).toBe('https://my-studio.sanity.studio')
   })
 
diff --git a/packages/@sanity/cli/src/actions/deploy/__tests__/deployRunner.test.ts b/packages/@sanity/cli/src/actions/deploy/__tests__/deployRunner.test.ts
index 50f4d6355..f39c4daa4 100644
--- a/packages/@sanity/cli/src/actions/deploy/__tests__/deployRunner.test.ts
+++ b/packages/@sanity/cli/src/actions/deploy/__tests__/deployRunner.test.ts
@@ -111,7 +111,12 @@ describe('runDeploy real deploy', () => {
     const result = {
       applicationType: 'studio' as const,
       applicationVersion: '3.99.0',
-      target: {applicationId: 'app-1', title: 'My Studio', url: 'https://my-studio.sanity.studio'},
+      target: {
+        action: 'update' as const,
+        applicationId: 'app-1',
+        title: 'My Studio',
+        url: 'https://my-studio.sanity.studio',
+      },
     }
     const spec: DeploySpec = {
       listFiles: async () => [],
diff --git a/packages/@sanity/cli/src/actions/deploy/__tests__/deploymentPlan.test.ts b/packages/@sanity/cli/src/actions/deploy/__tests__/deploymentPlan.test.ts
index 236da86e4..a135a3f6d 100644
--- a/packages/@sanity/cli/src/actions/deploy/__tests__/deploymentPlan.test.ts
+++ b/packages/@sanity/cli/src/actions/deploy/__tests__/deploymentPlan.test.ts
@@ -94,6 +94,7 @@ describe('deploymentPlanToJson', () => {
 
   test('passes the resolved target through to the JSON', () => {
     const target = {
+      action: 'update' as const,
       applicationId: 'app-1',
       title: 'My Studio',
       url: 'https://my-studio.sanity.studio',
diff --git a/packages/@sanity/cli/src/actions/deploy/__tests__/findUserApplication.test.ts b/packages/@sanity/cli/src/actions/deploy/__tests__/findUserApplication.test.ts
index 35115c589..e17c5231b 100644
--- a/packages/@sanity/cli/src/actions/deploy/__tests__/findUserApplication.test.ts
+++ b/packages/@sanity/cli/src/actions/deploy/__tests__/findUserApplication.test.ts
@@ -55,7 +55,7 @@ describe('findUserApplication', () => {
 })
 
 describe('findUserApplicationForStudio', () => {
-  test('should pass the title through when registering the configured host', async () => {
+  test('registering a configured host passes the title through and reports created', async () => {
     const created = {title: 'My Studio'} as UserApplication
     mockResolveStudio.mockResolvedValue({appHost: 'new-host', type: 'would-create'})
     mockCreate.mockResolvedValue(created)
@@ -73,6 +73,23 @@ describe('findUserApplicationForStudio', () => {
       body: {appHost: 'new-host', title: 'My Studio', type: 'studio', urlType: 'internal'},
       projectId: 'project-1',
     })
-    expect(result).toBe(created)
+    // Registering a new host is a create, not an update — see #1462 (bugbot).
+    expect(result).toEqual({application: created, created: true})
+  })
+
+  test('an existing host is an update, not a create', async () => {
+    const existing = {appHost: 'my-studio', title: 'My Studio'} as UserApplication
+    mockResolveStudio.mockResolvedValue({application: existing, type: 'found'})
+    const output = mockOutput()
+
+    const result = await findUserApplicationForStudio({
+      appId: 'app-1',
+      isExternal: false,
+      output,
+      projectId: 'project-1',
+    })
+
+    expect(mockCreate).not.toHaveBeenCalled()
+    expect(result).toEqual({application: existing, created: false})
   })
 })
diff --git a/packages/@sanity/cli/src/actions/deploy/deployApp.ts b/packages/@sanity/cli/src/actions/deploy/deployApp.ts
index c2fcb7567..877f6b04f 100644
--- a/packages/@sanity/cli/src/actions/deploy/deployApp.ts
+++ b/packages/@sanity/cli/src/actions/deploy/deployApp.ts
@@ -61,6 +61,7 @@ async function runAppDeployment(
   const {cliConfig, flags, output, sourceDir} = options
   const workDir = options.projectRoot.directory
   const organizationId = cliConfig.app?.organizationId
+  const appId = getAppId(cliConfig)
   const workbench = getWorkbench(cliConfig)
   const dryRun = !!flags['dry-run']
 
@@ -112,6 +113,7 @@ async function runAppDeployment(
   checkAppId(reporter, {cliConfig})
 
   let application: UserApplicationResolved | null = null
+  let appCreated = false
   if (flags.external) {
     reporter.report({
       message: EXTERNAL_APP_NOT_SUPPORTED,
@@ -121,13 +123,13 @@ async function runAppDeployment(
   } else if (deployApplication && workbench) {
     // Both modes, so a bad appId fails before the build rather than at the POST.
     await checkAppTarget(reporter, {
-      appId: getAppId(cliConfig),
+      appId,
       isWorkbenchApp: true,
       slug: workbench.slug,
       title: appTitle,
     })
   } else if (deployApplication) {
-    application = await resolveAppApplication(options, {dryRun, reporter})
+    ;({application, created: appCreated} = await resolveAppApplication(options, {dryRun, reporter}))
   }
 
   await checkBuild(reporter, {
@@ -243,13 +245,21 @@ async function runAppDeployment(
       title: appTitle,
       version,
     })
-    logAppDeployed({applicationId, cliConfig, organizationId, output, title: appTitle})
+    logAppDeployed({
+      applicationId,
+      cliConfig,
+      created: !appId,
+      organizationId,
+      output,
+      title: appTitle,
+    })
     return {
       applicationType: 'coreApp',
       applicationVersion: version,
       ...(exposes.length > 0 ? {exposes} : {}),
       ...(workbench.isSingleton === undefined ? {} : {isSingleton: workbench.isSingleton}),
       target: {
+        action: appId ? 'update' : 'create',
         applicationId,
         // A redeploy ignores the slug, so only a create reports the one it used.
         ...(appId ? {} : {slug}),
@@ -268,6 +278,7 @@ async function runAppDeployment(
   logAppDeployed({
     applicationId: application.id,
     cliConfig,
+    created: appCreated,
     organizationId: application.organizationId,
     output,
     title: application.title,
@@ -276,6 +287,7 @@ async function runAppDeployment(
     applicationType: 'coreApp',
     applicationVersion: version,
     target: {
+      action: appCreated ? 'create' : 'update',
       applicationId: application.id,
       title: application.title ?? null,
       url: getCoreAppUrl(application.organizationId, application.id),
@@ -290,7 +302,7 @@ async function runAppDeployment(
 async function resolveAppApplication(
   options: DeployAppOptions,
   {dryRun, reporter}: {dryRun: boolean; reporter: CheckReporter},
-): Promise<UserApplicationResolved | null> {
+): Promise<{application: UserApplicationResolved | null; created: boolean}> {
   const {cliConfig, flags, output} = options
   const organizationId = cliConfig.app?.organizationId ?? ''
   // Create name from --title or `app.title` config; blank falls back to the prompt
@@ -298,7 +310,7 @@ async function resolveAppApplication(
 
   if (dryRun) {
     await checkAppTarget(reporter, {appId: getAppId(cliConfig), organizationId, title})
-    return null
+    return {application: null, created: false}
   }
 
   let application = await findUserApplication({
@@ -314,9 +326,10 @@ async function resolveAppApplication(
     deployDebug('No user application found. Creating a new one')
     application = await createUserApplication(organizationId, title)
     deployDebug('User application created', application)
+    return {application, created: true}
   }
 
-  return application
+  return {application, created: false}
 }
 
 /** Syncs the application title from the manifest when it has changed. */
@@ -391,12 +404,14 @@ async function shipAppDeployment({
 export function logAppDeployed({
   applicationId,
   cliConfig,
+  created,
   organizationId,
   output,
   title,
 }: {
   applicationId: string
   cliConfig: DeployAppOptions['cliConfig']
+  created: boolean
   organizationId: string
   output: DeployAppOptions['output']
   title: string | null
@@ -404,10 +419,19 @@ export function logAppDeployed({
   const url = getCoreAppUrl(organizationId, applicationId)
   const named = title ? ` — "${title}"` : ''
   output.log(`\nSuccess! Application deployed to ${styleText('cyan', url)}${named}`)
+  output.log(created ? 'Created a new application.' : 'Updated the existing application.')
 
   if (getAppId(cliConfig)) return
 
   output.log(`\n════ ${styleText('bold', 'Next step:')} ════`)
+  if (created) {
+    output.log(
+      styleText(
+        'yellow',
+        '\nDeploying again without `deployment.appId` creates another new application.',
+      ),
+    )
+  }
   output.log(
     styleText('bold', '\nAdd the deployment.appId to your sanity.cli.js or sanity.cli.ts file:'),
   )
diff --git a/packages/@sanity/cli/src/actions/deploy/deployChecks.ts b/packages/@sanity/cli/src/actions/deploy/deployChecks.ts
index 95db5ab5c..ce6cfc426 100644
--- a/packages/@sanity/cli/src/actions/deploy/deployChecks.ts
+++ b/packages/@sanity/cli/src/actions/deploy/deployChecks.ts
@@ -31,6 +31,8 @@ type DeployCheckStatus = 'fail' | 'pass' | 'skip' | 'warn'
  * can't drift.
  */
 export interface DeployTarget {
+  /** Whether the deploy creates a new application/studio or updates an existing one. */
+  action: 'create' | 'update'
   /** The application the deploy targets; `null` when a deploy would create one. */
   applicationId: string | null
   /** The application's title; `null` when it has none (or isn't created yet). */
@@ -261,7 +263,12 @@ export function describeAppTarget(
       return {
         message: `Deploys to existing application "${title}" at ${url}`,
         status: 'pass',
-        target: {applicationId: application.id, title: application.title ?? null, url},
+        target: {
+          action: 'update',
+          applicationId: application.id,
+          title: application.title ?? null,
+          url,
+        },
       }
     }
     case 'invalid': {
@@ -285,7 +292,13 @@ export function describeAppTarget(
         return {
           message: `Would create a new application "${title}"${slug ? ` with slug "${slug}"` : ''}`,
           status: 'pass',
-          target: {applicationId: null, ...(slug ? {slug} : {}), title, url: null},
+          target: {
+            action: 'create',
+            applicationId: null,
+            ...(slug ? {slug} : {}),
+            title,
+            url: null,
+          },
         }
       }
       return {
@@ -363,6 +376,7 @@ export function describeStudioTarget(
         message: `Deploys to existing studio ${url}`,
         status: 'pass',
         target: {
+          action: 'update',
           applicationId: resolution.application.id,
           title: resolution.application.title ?? null,
           url,
@@ -398,7 +412,7 @@ export function describeStudioTarget(
         status: 'pass',
         // `title || null`, not `?? null`, so target.title tracks the same
         // truthiness the message's `titled` suffix uses (an empty title is no title)
-        target: {applicationId: null, title: title || null, url},
+        target: {action: 'create', applicationId: null, title: title || null, url},
       }
     }
   }
diff --git a/packages/@sanity/cli/src/actions/deploy/deployStudio.ts b/packages/@sanity/cli/src/actions/deploy/deployStudio.ts
index 57fa47e67..52846ad92 100644
--- a/packages/@sanity/cli/src/actions/deploy/deployStudio.ts
+++ b/packages/@sanity/cli/src/actions/deploy/deployStudio.ts
@@ -58,6 +58,7 @@ async function runStudioDeployment(
   const isWorkbenchApp = workbench !== null
   const projectId = cliConfig.api?.projectId
   const organizationId = cliConfig.app?.organizationId
+  const appId = getAppId(cliConfig)
   const dryRun = !!flags['dry-run']
 
   // A federated app deploys through Sanity's build/hosting pipeline, which
@@ -95,6 +96,7 @@ async function runStudioDeployment(
   // Workbench studios deploy to Brett (which needs the org); plain studios
   // resolve/create on user-applications, unchanged.
   let application: UserApplication | null = null
+  let studioCreated = false
   let studioTarget: DeployTarget | null = null
   if (workbench && !isExternal) {
     reporter.report(
@@ -109,13 +111,16 @@ async function runStudioDeployment(
     // Both modes, so a bad appId fails before the build; its resolved URL feeds
     // the deploy result.
     studioTarget = await checkStudioTarget(reporter, {
-      appId: getAppId(cliConfig),
+      appId,
       isWorkbenchApp: true,
       studioHost: cliConfig.studioHost,
       title: appTitle,
     })
   } else {
-    application = await resolveStudioApplication(options, {dryRun, reporter})
+    ;({application, created: studioCreated} = await resolveStudioApplication(options, {
+      dryRun,
+      reporter,
+    }))
   }
 
   await checkBuild(reporter, {
@@ -152,7 +157,7 @@ async function runStudioDeployment(
   // Workbench studios deploy to Brett; plain studios use user-applications.
   if (workbench && !isExternal && organizationId) {
     const {applicationId} = await deployWorkbenchStudio({
-      appId: getAppId(cliConfig),
+      appId,
       interfaces: buildExposes(workbench, {
         appName: workbench.name,
         appTitle,
@@ -174,7 +179,12 @@ async function runStudioDeployment(
       applicationType: 'studio',
       applicationVersion: version,
       ...(exposes.length > 0 ? {exposes} : {}),
-      target: {applicationId, title: appTitle, url: studioTarget?.url ?? null},
+      target: {
+        action: appId ? 'update' : 'create',
+        applicationId,
+        title: appTitle,
+        url: studioTarget?.url ?? null,
+      },
     }
   }
 
@@ -191,7 +201,12 @@ async function runStudioDeployment(
   return {
     applicationType: 'studio',
     applicationVersion: version,
-    target: {applicationId: application.id, title: application.title ?? null, url: location},
+    target: {
+      action: studioCreated ? 'create' : 'update',
+      applicationId: application.id,
+      title: application.title ?? null,
+      url: location,
+    },
   }
 }
 
@@ -202,27 +217,29 @@ async function runStudioDeployment(
 async function resolveStudioApplication(
   options: DeployAppOptions,
   {dryRun, reporter}: {dryRun: boolean; reporter: CheckReporter},
-): Promise<UserApplication | null> {
+): Promise<{application: UserApplication | null; created: boolean}> {
   const {cliConfig, flags, output} = options
   const isExternal = !!flags.external
+  const appId = getAppId(cliConfig)
   // Sets the title on a newly registered studio; blank falls back to undefined
   const title = flags.title?.trim() || undefined
 
   if (dryRun) {
     await checkStudioTarget(reporter, {
-      appId: getAppId(cliConfig),
+      appId,
       isExternal,
       projectId: cliConfig.api?.projectId,
       studioHost: cliConfig.studioHost,
       title,
       urlFlag: flags.url,
     })
-    return null
+    return {application: null, created: false}
   }
 
   const projectId = cliConfig.api?.projectId ?? ''
-  let application = await findUserApplicationForStudio({
-    appId: getAppId(cliConfig),
+  // `created` is true when a configured-but-unregistered host was just registered.
+  const {application, created} = await findUserApplicationForStudio({
+    appId,
     isExternal,
     output,
     projectId,
@@ -242,16 +259,17 @@ async function resolveStudioApplication(
       output.log('you will need one. Please enter the subdomain you want to use.')
     }
 
-    application = await createStudioUserApplication({
+    const registered = await createStudioUserApplication({
       projectId,
       title,
       urlType: isExternal ? 'external' : 'internal',
     })
-    deployDebug('Created user application', application)
+    deployDebug('Created user application', registered)
+    return {application: registered, created: true}
   }
 
   deployDebug('Found user application', application)
-  return application
+  return {application, created}
 }
 
 /** Extracts the studio schema and manifest and uploads them to the schema store. */
diff --git a/packages/@sanity/cli/src/actions/deploy/findUserApplication.ts b/packages/@sanity/cli/src/actions/deploy/findUserApplication.ts
index 44e1f18e3..6dba5b8e1 100644
--- a/packages/@sanity/cli/src/actions/deploy/findUserApplication.ts
+++ b/packages/@sanity/cli/src/actions/deploy/findUserApplication.ts
@@ -90,7 +90,7 @@ interface FindUserApplicationForStudioOptions {
 
 export async function findUserApplicationForStudio(
   options: FindUserApplicationForStudioOptions,
-): Promise<UserApplication | null> {
+): Promise<{application: UserApplication | null; created: boolean}> {
   const {
     appId,
     isExternal,
@@ -118,31 +118,37 @@ export async function findUserApplicationForStudio(
     spin.fail()
     deployDebug('Error finding user application', error)
     output.error(`Failed to resolve deploy target: ${getErrorMessage(error)}`, {exit: 1})
-    return null
+    return {application: null, created: false}
   }
 
   if (resolution.type === 'found') {
     spin.succeed()
-    return resolution.application
+    return {application: resolution.application, created: false}
   }
 
-  // The configured host isn't registered yet — a deploy registers it without prompting
+  // The configured host isn't registered yet — a deploy registers it without
+  // prompting, so this returns a newly created studio.
   if (resolution.type === 'would-create') {
     spin.succeed()
-    return createFromConfiguredHost({
+    const application = await createFromConfiguredHost({
       appHost: resolution.appHost,
       output,
       projectId,
       title,
       urlType,
     })
+    return {application, created: application !== null}
   }
 
   if (resolution.type === 'needs-input' && !unattended) {
     spin.succeed()
     // Nothing to select from — the caller prompts for a brand new host
-    if (resolution.existing.length === 0) return null
-    return promptForExistingStudio({existing: resolution.existing, urlType})
+    if (resolution.existing.length === 0) return {application: null, created: false}
+    // A selected existing studio is an update; "new" returns null and the caller registers it.
+    return {
+      application: await promptForExistingStudio({existing: resolution.existing, urlType}),
+      created: false,
+    }
   }
 
   spin.fail()
@@ -150,10 +156,10 @@ export async function findUserApplicationForStudio(
   // needs an explicit exit here
   if (resolution.type === 'blocked') {
     output.error(resolution.message, {exit: 1})
-    return null
+    return {application: null, created: false}
   }
   createFailFastReporter(output).report(describeStudioTarget(resolution, {isExternal}))
-  return null
+  return {application: null, created: false}
 }
 
 /**
diff --git a/packages/@sanity/cli/test/integration/commands/deploy.app.test.ts b/packages/@sanity/cli/test/integration/commands/deploy.app.test.ts
index 8e886d2ee..b7a2c6467 100644
--- a/packages/@sanity/cli/test/integration/commands/deploy.app.test.ts
+++ b/packages/@sanity/cli/test/integration/commands/deploy.app.test.ts
@@ -374,6 +374,7 @@ describe('#deploy app', () => {
     const plan = JSON.parse(stdout)
     expect(plan.isDeployable).toBe(true)
     expect(plan.target).toEqual({
+      action: 'create',
       applicationId: null,
       slug: 'drop-desk-host',
       title: 'Workbench App',