Understanding Throttling in Power Automate: Why It Happens & How to Fix It

 Power Automate is a powerful automation platform, but like any cloud service, it enforces certain usage limits to keep things stable and fair for all users. When your flows exceed those limits, throttling kicks in.

In this article, you’ll learn what throttling is, why it happens, how to avoid it, and real-world strategies to make your flows run smoothly—even under heavy load.

---

🚦 What Is Throttling in Power Automate?

Throttling occurs when Power Automate temporarily slows down or blocks your flow’s actions because they exceed the allowed API or connector limits.

Think of it as a traffic signal for automation—when too many cars (API calls) rush through at once, throttling regulates the traffic to prevent system overload.

---

🚨 When Does Throttling Occur?

Your flow may get throttled in situations like:

🔹 1. Too many API calls in a short time

For example: A loop running 500 items with a SharePoint action inside can easily hit API limits.

🔹 2. High concurrency

Parallel branches or concurrency-enabled loops can fire several actions simultaneously.

🔹 3. Exceeding connector-specific limits

Every connector has its own documented limits. Exceed them, and 429 (Too Many Requests) errors begin to appear.

---

📊 Common Connector Limits to Watch

Connector	Limit	Impact
SharePoint	~600 calls/min	Flow retries or fails
Outlook	100 emails/hour	Email delays, failures, or skipped sends
Dataverse	1,000 requests per 5 minutes	Throttling, slowdowns, or 429 errors

Knowing these limits is essential for properly designing scalable flows.

---

🛠️ How to Fix or Prevent Throttling in Power Automate

Here are proven techniques to avoid hitting connector limits:

✅ 1. Enable Retry Policies with Exponential Backoff

Retry policies automatically re-execute actions when they encounter 429 errors.
This spreads out the load without manual intervention.

✅ 2. Add Delay or Delay Until Actions

Spacing out API calls gives Power Automate breathing room.
A simple 10–30 second delay can make a huge difference.

✅ 3. Optimize Loops with Batching

Instead of processing items one at a time, send them in batches:

• Use "Send an HTTP request to SharePoint" batching API

• Use Data Operations → Compose/Parse JSON to handle grouped data

• Reduce the number of overall connector calls

✅ 4. Split Logic Across Child Flows

Offload heavy tasks to secondary flows.
This improves performance and avoids hitting per-flow limits.

---

🧠 Governance Tips for Organizations

Throttling isn’t just a technical concern—it’s a governance and scaling concern.

Here’s how to build a throttling-resistant automation environment:

✔️ Document connector limits

Include them in your onboarding kits or COE documentation.

✔️ Use Connection References

Isolate high-usage flows from each other.

✔️ Monitor with the CoE Starter Kit

The COE Audit Logs and dashboards can alert you before throttling becomes an issue.

✔️ Train teams to handle 429 errors

Give makers best practices for flow design and error recovery.

---

📘 Real-World Scenario

Let’s bring this to life with a practical example.

🎯 Scenario

A confirmation email is sent to each user who submits a form. During peak hours, the system sends 150+ emails per hour using the Outlook connector.

❗ Problem

Outlook has a strict limit: 100 emails per hour per connection.
When the flow exceeds this:

• Emails fail

• Flows skip actions

• 429 throttling errors appear

🛠️ Solution Breakdown

✅ Step 1: Add Delay Between Emails

Insert a Delay (30 seconds) after each "Send Email" action.
This spaces requests and keeps the flow under Outlook's hourly cap.

✅ Step 2: Use Exponential Retry Policy

Within the "Send an Email" advanced settings:

• Set retry policy to Exponential

• Limit the attempts appropriately

This allows your flow to automatically recover from throttling.

✅ Step 3: Split the Flow into Child Flows

Create two child flows, each sending ~75 emails/hour.
Use "Run a Child Flow" to distribute the load cleanly.

✅ Step 4: Use Multiple Connections (Optional)

Using two service accounts splits throttling limits across accounts.
This is common in enterprise-scale automation.

---

💡 Final Thought

Throttling is not a bug—it’s a signal.
A well-designed Power Automate solution anticipates throttling and uses smart techniques like batching, retry policies, and child flows to handle high volume gracefully.

By understanding your connector limits and optimizing your flows, you’ll create resilient, scalable, and enterprise-ready automations.