Fix SharePoint List Integration Field Limit & Power Automate Timeouts

Categorize your 120 fields into three logical sets of approximately 40 fields each (e.g., Basic Info, Additional Details, and System Data).

Set up a Power Automate flow that triggers on form submission. Configure it to write only the first group of 40 fields to the SharePoint list. Ensure this action outputs the newly created SharePoint Item ID.

Create one or two secondary flows. Use the 'Update item' SharePoint action, referencing the Item ID generated by the primary flow, to map and save the remaining field groups.

Run a test submission through your custom form. Verify that the primary flow creates the record and the secondary flows successfully append the remaining data without timing out.

Review your list and identify optional form fields, historical logs, or extended details that do not need to reside in the primary view.

Navigate to Site Contents and create a new list dedicated to storing these specific fields. Ensure it has a column to store a unique identifier.

In your primary SharePoint list, go to List Settings and create a 'Lookup' column that references the unique identifier from your newly created related list.

Adjust your Power Automate flows to create the primary record first, then use a separate action to create the associated record in the related list, ensuring both lists stay well below the 120-field threshold.

Develop a custom web service or Azure Function that accepts the entire custom form payload and uses the SharePoint REST API to batch create or update the list item.

Register your new custom API in Azure Active Directory to handle secure authentication between Power Automate and your service.

In your flow, replace the standard 'Create item' SharePoint connector with an 'HTTP' action. Send the form data payload to your custom API endpoint, which will process the 120+ fields without triggering standard connector timeouts.