Microsoft ACS Retirement: Finding an SMS API You Can Trust

Microsoft has announced the retirement of standalone Azure Communication Services (ACS) SMS. For enterprises running automated workflows in Azure Logic Apps, Power Automate, and Copilot Studio, this means planning for a replacement that can support their long-term messaging needs. Microsoft recommends migrating business messaging to specialized providers in its ecosystem.

Choosing a replacement also means looking at how it handles volume, compliance, and resilience in the face of mission critical messages. Here’s how Retarus’ SMS API for Microsoft, now listed on Microsoft Learn, handles these major considerations.

Send Up to 3,000 Recipients Personalized or Broadcast SMS in One Call

One major limitation of many SMS API providers is they accept only one phone number per call. Even the few connectors that support multiple recipients can only send the same broadcast text to everyone. When a workflow needs to send personalized SMS messages to hundreds of customers, each with its own order number, flight gate, or appointment time, conventional connectors require repeated loops. These loops slow down processing, increase workflow costs, and can quickly reach platform throttling limits.

The certified Retarus SMS Connector uses an enterprise job model that supports multiple messages and recipients in a single call. As part of Retarus’ SMS API for Microsoft, it supports both of the following scenarios:

One broadcast alert to up to 3,000 recipients: Send the same urgent update to 300 passengers on a delayed flight or an entire on-call team in one step.

Hundreds of personalized texts in the same batch: Bundle hundreds of custom messages in the same API call, each with its own dynamic text and customerRef pulled directly from SAP S/4HANA, Microsoft Dynamics 365, or SharePoint. Each customer receives their individual confirmation, while Azure Logic Apps or Power Automate executes just one action.

Reduce SMS Workflow Costs and Simplify Delivery Management

Submitting hundreds of personalized or broadcast texts in a single step reduces the repeated calls that can reach Microsoft’s 100-calls-per-minute connector cap. It also helps lower workflow action costs by up to 99%: instead of running 500 loop iterations in Azure Logic Apps or Power Automate, teams can submit the entire batch through one action.

Enterprise governance features are built in, too. Teams can manage cost-center billing (billcode), Express priority routing, and blackout periods, while tracking delivery across the batch through a single jobId.

Three SMS Use Cases for Microsoft Workflows

1. Order, booking, and appointment confirmations: Collect pending confirmations from your ERP or CRM every 5 or 15 minutes, then send hundreds of personalized texts in one cost-efficient batch call. For individual events that require sub-second processing, such as real-time two-factor authentication (2FA) or one-time password (OTP) codes, the direct Retarus REST API complements the connector.
2. Travel, aviation, and logistics: Notify more than 300 passengers about a gate change or delay, or send delivery updates, in a single workflow step. Send a group broadcast or personalize each message with an individual booking reference.
3. IT incident alerting and field operations: Alert entire on-call rosters, branch managers, or field technicians immediately when critical events occur in ServiceNow, Azure Monitor, or Microsoft Teams.

Enterprise SMS with Regional Data Centers and Direct Carrier Routing

Workflow efficiency is one part of the decision. Retarus Enterprise SMS also provides the data protection and routing quality that regulated enterprises require:

Regional data sovereignty: Messages are processed in Retarus’ own, self-operated, auditable data centers in Europe (Munich, Frankfurt, and Zurich), the US, and APAC, with zero cross-border data transfer and full compliance with GDPR, HIPAA, TISAX, ISO/IEC 27001, and SOC 1 / SOC 2 Type II.

Direct carrier routing without grey routes: With connections to 99% of global mobile networks, active multi-carrier management, and delivery rates above 99.9%, Retarus guarantees reliable handoff within milliseconds worldwide.

Ready to upgrade your Microsoft workflows? Explore the official Retarus SMS Connector on Microsoft Learn and see how Retarus’ Microsoft integrations support your wider messaging environment.