Customer.io

customer.io · email

Customer.io declares 9 subprocessors in its subprocessor list, which we last checked on Nov 11, 2026 (evidence). They include Amazon Web Services, Google Cloud and OpenAI. No published changes since we first read it on Sep 22, 2026. 112 tracked vendors name Customer.io as a subprocessor, including Notion, OpenRouter and Plain.

Subprocessors CSV · Atom DORA draft CSV what's this? · 

9 third parties.

NamePurposeLocationListed since
Amazon Web Services Cloud HostingUSA, EU
Anthropic (Claude) AIAI model hosting and inference for optional AI-powered featuresUSA
Google Cloud (Vertex AI) AIAI model hosting and inference for optional AI-powered featuresUSA, EU
Google Cloud Platform Cloud Hosting, Analytics, AIUSA, EU
Infobip Customer Communications*USA, EU
Mailgun Customer CommunicationsUSA, EU
OpenAI, LLC AIAI model inference for optional AI-powered featuresUSA, EU
Snowflake Data Warehousing, AnalyticsUSA, EU
Twilio Customer Communications*USA

Web TechnologiesCSV · Atom

Customer.io's homepage made 90 requests to 7 domains, and 3 services controlled by another company.

Analytics (1): Google CloudCookie compliance (1): CookiebotOther (1): usually detected as CMS: Sanity

3 third parties by category: Analytics 1Cookie compliance 1Other 1

Third parties 3 · 23 requests
Sanity sanity.io 12% of the page's requests 11
Google Cloudsubprocessor Google Analytics Google Tag Manager 9% of the page's requests 8
Cookiebot Cookiebot 1 4% of the page's requests 4
First party 1 · 67 requests
Customer.io Customer.io Framer Motion HSTS LottieFiles Next.js 15.5.24 Next.js App Router Open Graph PWA Priority Hints Radix UI React Sanity Sanity.io Segment 0.8.2 Sentry Vercel Vercel Analytics Vercel Speed Insights 1.3.1 Webpack 74% of the page's requests 67

2 tracked companies loaded by the homepage are not in Customer.io's subprocessor list. A website can use a service without it processing customer data.

Subprocessor of (112)CSV · Atom

112 companies
  • 123FormBuilder 123formbuilder.com
  • Aaru aaru.com Customer communications; Notifications / messaging
  • Abusix abusix.com Customer Communication
  • Akiflow akiflow.com Conversational support, customers onboarding, conversion analysis and drop-off, measurement of active usage, retention drivers
  • Anaconda anaconda.com Email sending
  • Archbee archbee.com Customer Service
  • Arphie arphie.ai
  • Asanify asanify.com Transactional and marketing emails
  • Atomic.io atomic.io Email communications
  • Axiom axiom.co Transactional, broadcast, and marketing messaging; Used for marketing
  • Balsamiq balsamiq.com Product and marketing email delivery
  • BetterCloud bettercloud.com Customer Service; [Website]( Sends application emails for customer configured alerts.
  • BioRender biorender.com
  • Buffer buffer.com
  • Candu candu.ai Communication marketing and customer support services; Sales / Marketing
  • Canopy canopy.is Announcements & Email makerting
  • Capacity capacity.com Enables automated outbound messaging and behavioral-triggered email notifications for Outbound Campaigns.; Outbound customer messaging
  • Captain Data captaindata.com Transactional and lifecycle emails
  • Chainloop chainloop.dev customer.io
  • Chameleon Intelligent Tech chameleon.io Communications and Personalization
  • ChargeOver chargeover.com Sending email to customers
  • Clarity clarity.com
  • Close close.com Transactional emails
  • CodeRabbit coderabbit.ai Customer Communications
  • CometChat cometchat.com
  • Cooby cooby.co Marketing automation and customer messaging
  • Cyberbit cyberbit.com Transactional and operational messaging Annex IV to the DPA; Transactional and operational messaging Providing support and chat
  • DataCamp datacamp.com Customer.io provides a number of email related services, including distribution automated transactional email functions (such as password resets) and platform email functions (such as distribution of statement of accomplishments). In addition, customer.io provides certain email functions for distribution of engagement and platform educational materials, which Customer or its Business Users may opt out of receiving.; Email services
  • Daytona daytona.io Customer Communication
  • Dust dust.tt Message Workflow
  • Dynamiq getdynamiq.ai Customer communications, onboarding, and transactional emails
  • Edmentum edmentum.com Adult roles; ALVS Purchasers: Parent/Guardian; Marketing Communications Automation; Customer Data Platform for ALVS
  • Enboarder enboarder.com
  • Featurebase featurebase.app Email communication with Customer admins
  • Fly.io fly.io Newsletters and transactional email
  • Foqal foqal.io Marketing Automation
  • Forest Admin forest.app
  • Fountain fountain.com Marketing and messaging automation
  • Frill frill.co Support
  • Gamma gamma.app Customer communications
  • GitGuardian gitguardian.com Data analytics allowing user dashboard, behavior monitoring and profile data on Platform and Public Monitoring
  • Gorgias gorgias.com Customer communication
  • Graphite graphite.dev
  • groundcover groundcover.com Communications
  • Harvest getharvest.com Marketing processor
  • Hookdeck hookdeck.com Emails
  • HowToo howtoo.co United States - transactional and reminder email delivery
  • Hubstaff hubstaff.com Communications / Marketing Automation; Platform for personalized messaging and automated customer journeys.
  • Inngest inngest.com
  • Kanbanchi kanbanchi.com Customer communication and engagement
  • Khoros khoros.ai CRM
  • Konvu konvu.com Transactional and product alert email delivery
  • Lago getlago.com Delivery of Lago's own product and lifecycle communications to its customers. Does not deliver emails sent on behalf of customers. Processes email addresses and customer identifiers.
  • LeadMagic leadmagic.io Lifecycle messaging, product emails, and related customer communication workflows.
  • Lovable lovable.dev Customer engagement
  • Marker.io marker.io Transactional & marketing messaging
  • Mercor mercor.com
  • Metabase metabase.com Email communications.
  • Mida mida.so Customer engagement platform
  • Mixmax mixmax.com Customer Messaging
  • Notion notion.com Transactional, broadcast, and marketing messaging
  • One Horizon onehorizon.ai Product messaging and email campaigns
  • OpenRouter openrouter.ai Email Notifications
  • OpenSesame opensesame.com Messaging
  • OptiSigns optisigns.com Customer communication
  • Parabola parabola.io Customer messaging
  • Paved paved.com Customer Communications
  • People.ai people.ai Processing operational customer data
  • Pilosa pilosa.com Email communication with Customer admins
  • Pipeline CRM pipelinecrm.com Messaging; Product and lifecycle messaging to customers' users
  • Plain plain.com Marketing; Marketing Analytics
  • Popupsmart popupsmart.com Customer messaging, lifecycle emails, and automation
  • PowerSchool powerschool.com Email Communications
  • Product Fruits productfruits.com Marketing, newsletters
  • Push Security pushsecurity.com
  • pydantic pydantic.dev Marketing and lifecycle emails
  • Quo quo.com Email marketing; Marketing Automation
  • Railway railway.com Platform and Marketing Messaging
  • Read AI read.ai Customer Engagement
  • Refiner refiner.io Customer messaging and email delivery platform used for transactional and product-related communications.
  • Relay Commerce relaycommerce.io
  • Responsly responsly.com Transactional, informational and marketing messages to Customers
  • Rows rows.com CRM emails services
  • Scalr scalr.io Marketing
  • ScrapingBee scrapingbee.com Transactional & Marketing Email
  • Scratchpad scratchpad.com Email marketing
  • SigNoz signoz.io
  • SMTP2GO smtp2go.com Customer Communication
  • SocialPilot socialpilot.co Email Communication
  • SquaredUp squaredup.com Marketing / Analytics
  • Terramate terramate.io
  • Textline textline.com System and Marketing Emails
  • tl;dv tldv.io Marketing
  • Tomorro tomorro.com
  • Trickest trickest.com Account and product emails
  • Tuple tuple.app Email campaigns for onboarding and app updates
  • Type type.com
  • Uhubs uhubs.co.uk
  • Unified.to unified.to Product emails
  • Upstash upstash.com
  • Urlbox urlbox.com Marketing Emails sent via Customer.io
  • UserCheck usercheck.com Email automation
  • Vacation Tracker vacationtracker.io Customer success; Drip email campaigns
  • Validity validity.com Business Operations; Customer Communications
  • Vev vev.design Market communications of Vev service.
  • Viktor getviktor.com Customer messaging/notifications (if used)
  • Warp warp.dev
  • Whimsical whimsical.com Email service provider
  • Woopra woopra.com Software as a service (SaaS) enabling users to send personalized newsletters using website data
  • Yoodli yoodli.ai Product and marketing emails
  • Yotpo yotpo.com Email service provider
  • YuLife yulife.com Mobile Marketing & Engagement

Service statusCSV · Atom

Aug 15: no incident reportedAug 16: no incident reportedAug 17: no incident reportedAug 18: no incident reportedAug 19: no incident reportedAug 20: no incident reportedAug 21: no incident reportedAug 22: no incident reportedAug 23: no incident reportedAug 24: no incident reportedAug 25: no incident reportedAug 26: no incident reportedAug 27: no incident reportedAug 28: no incident reportedAug 29: no incident reportedAug 30: no incident reportedAug 31: no incident reportedSep 1: no incident reportedSep 2: no incident reportedSep 3: 1 incident (1 minor)Sep 4: 1 incident (1 no impact stated)Sep 5: no incident reportedSep 6: no incident reportedSep 7: no incident reportedSep 8: no incident reportedSep 9: no incident reportedSep 10: no incident reportedSep 11: no incident reportedSep 12: no incident reportedSep 13: no incident reportedSep 14: no incident reportedSep 15: no incident reportedSep 16: no incident reportedSep 17: no incident reportedSep 18: no incident reportedSep 19: 1 incident (1 minor)Sep 20: no incident reportedSep 21: no incident reportedSep 22: no incident reportedSep 23: no incident reportedSep 24: no incident reportedSep 25: no incident reportedSep 26: no incident reportedSep 27: no incident reportedSep 28: no incident reportedSep 29: no incident reportedSep 30: no incident reportedOct 1: no incident reportedOct 2: no incident reportedOct 3: no incident reportedOct 4: no incident reportedOct 5: no incident reportedOct 6: no incident reportedOct 7: no incident reportedOct 8: no incident reportedOct 9: no incident reportedOct 10: no incident reportedOct 11: no incident reportedOct 12: no incident reportedOct 13: no incident reportedOct 14: no incident reportedOct 15: no incident reportedOct 16: no incident reportedOct 17: no incident reportedOct 18: no incident reportedOct 19: no incident reportedOct 20: no incident reportedOct 21: no incident reportedOct 22: no incident reportedOct 23: no incident reportedOct 24: no incident reportedOct 25: no incident reportedOct 26: no incident reportedOct 27: 1 incident (1 minor)Oct 28: no incident reportedOct 29: no incident reportedOct 30: no incident reportedOct 31: no incident reportedNov 1: no incident reportedNov 2: no incident reportedNov 3: no incident reportedNov 4: no incident reportedNov 5: no incident reportedNov 6: 1 incident (1 major)Nov 7: no incident reportedNov 8: no incident reportedNov 9: no incident reportedNov 10: no incident reportedNov 11: no incident reportedNov 12: no incident reported

90 days agotoday

  • 5 incidents in 90 days
  • 1 major or critical
  • 27 min typical time to resolve
  • 30 min longest major
BeganIncidentImpactLasted
Customers are Unable to add new Email Sending Domainsmajor30 min
Customer.io UI is currently unavailable for some customersminor24 min
Some US customers may experience delays in message sendingminor27 min
Reduced Deliverability to Microsoft-Hosted Email Addressesno impact stated1 h 19 min
Investigating issues with the Agentminor4 min
Customer.io UI is inaccessibleno impact stated26 min
Delays in processing and UI inaccessible for some customers in the US datacentreminor33 min
Issues accessing EU accountsmajor15 min

Incidents per month

0 5 10 Dec 2025: 4 incidents (4 minor) · typical time to resolve 1 h 31 min Jan 2026: 3 incidents (1 minor, 2 no impact stated) · typical time to resolve 30 min Feb 2026: 3 incidents (2 minor, 1 no impact stated) · typical time to resolve 20 min Mar 2026: 3 incidents (1 minor, 2 no impact stated) · typical time to resolve 25 min Apr 2026: 7 incidents (2 major, 2 minor, 3 no impact stated) · typical time to resolve 10 min May 2026: 3 incidents (3 minor) · typical time to resolve 42 min Jun 2026: 9 incidents (2 major, 6 minor, 1 no impact stated) · typical time to resolve 1 h 5 min Jul 2026: 8 incidents (2 major, 5 minor, 1 no impact stated) · typical time to resolve 1 h 22 min Aug 2026: 2 incidents (1 minor, 1 no impact stated) · typical time to resolve 33 min Sep 2026: 3 incidents (2 minor, 1 no impact stated) · typical time to resolve 27 min Oct 2026: 1 incident (1 minor) · typical time to resolve 24 min Nov 2026: 1 incident (1 major) · typical time to resolve 30 min Dec 2025Jan 2026Feb Mar Apr May Jun Jul Aug Sep Oct Nov

critical major minor no impact stated

Components affected

ComponentIncidents
Management Interface2
Message Sending2

As Customer.io's status page reports its own incidents (scheduled maintenance left out), read every few hours since (evidence)

Incidents reported by Customer.io's subprocessorsCSV · Atom

269 reported incidents in the last 30 days, by 6 of the vendors Customer.io lists as subprocessors.

A subprocessor list names a company, not the service an incident touched. This does not show that Customer.io was involved.

DateCompanyIncidentImpactLasted
OpenAIGPT-image-2.5 and 2.6 Sunburst & Flare High error rate minor32 min
SnowflakeINC20000347 minor32 min
TwilioMMS Delivery Failures from Twilio to GCI United States minor3 min
TwilioSMS Delivery Failures from Twilio 10DLC to AT&T United States minor4 h 3 min
TwilioSMS Delivery Failures from Twilio to Orange Sierra Leone minorongoing
TwilioSMS Delivery Failures From Long Code Numbers to AT&T in the US minor1 h 19 min
TwilioSMS Delivery Delays from Twilio to MTS Kazakhstan minorongoing
TwilioSMS Delivery Failures from a Subset of Twilio Phone Numbers to Tcell Tajikistan minor11 h 19 min
OpenAIUnable to start new Workspace Agent runs critical9 h 42 min
TwilioMMS Delivery Delays from a Subset of Twilio Long Codes to Multiple Small Networks in United States minorongoing
TwilioSMS Delivery Failures from a Subset of Twilio Phone Numbers to K-Cell Kazakhstan minor7 h 23 min
OpenAIElevated errors affecting logins, sign-ups, and ChatGPT features minor8 min
TwilioVoice Call Failures in JP1 minor3 h 51 min
InfobipMultiple Location - WhatsApp Sender Registrations Failure minor3 h 4 min
TwilioSMS Delivery Failures from Twilio to Turkcell Turkey minor3 h 54 min
TwilioRetroactive Incident Impacting Twilio Usage APIs no impact stated1 min
AnthropicElevated errors on Fable 52 and Mythos 52 no impact stated1 min
TwilioIssue resolved minor1 h 43 min
TwilioSMS Delivery Receipt Delays from Twilio Phone Numbers to Movistar Venezuela minor3 h 26 min
TwilioGateway API (Lookup API) Failure Increase on Verizon in United States minor10 h 23 min
OpenAIIncorrect cost data in Costs API exports no impact stated2 h 20 min
InfobipGlobal (Europe) - Email Service Degradation minor6 h 12 min
OpenAIElevated Errors On API minor42 min
TwilioWhatsApp Business API Message Send Failures minor16 h 29 min
OpenAIElevated ChatGPT Conversation Errors minor52 min

And 244 more. All of them: CSV · Who is around them.

ChangesCSV · Atom

See the list as we read it on any date: Time machine

None since tracking began.

Rating badge for Customer.io's site

Customer.io transparency rating

It updates with the rating.

<a href="https://thirdpartyindex.com/vendors/customer-io"><img src="https://thirdpartyindex.com/badge/customer-io.svg" alt="Customer.io transparency rating on Third Party Index" height="20"></a>
[![Customer.io transparency rating on Third Party Index](https://thirdpartyindex.com/badge/customer-io.svg)](https://thirdpartyindex.com/vendors/customer-io)