HubSpot /2026-09/ API Version

HubSpot officially rolled out its /2026-09/ API version, which strictly enforces admin-configured validation rules across all CRM API write paths. Integrations writing to endpoints like /crm/v3/objects/contacts or /crm/v3/objects/deals will no longer bypass required fields or invalid property formats. Any API request attempting to create or update a record without meeting your portal's exact data entry rules will now throw a hard error.

This directly affects core agency automation pipelines like lead intake forms, webhooks from landing pages, and organic lead capture flows. If your Make or Zapier scenarios pass partial lead data or miss a field that your CRM admin set as mandatory, the pipeline will break instantly instead of silently creating incomplete records. While this protects client data hygiene for attribution reporting and AI search optimization tools, it risks losing live inbound leads if your payload formats do not align with portal settings.

Operations teams need to take these steps right now to prevent pipeline failures:

• 1Audit every active Make scenario, Zap, and custom webhook sending data to HubSpot to confirm all mandatory object properties are included in the payload.
• 2Check portal settings under Properties to verify required fields for contacts, companies, and deals, matching them directly with your form inputs.
• 3Update your integration API request headers to target the /2026-09/ endpoint version so your code handles the new error responses cleanly.
• 4Add error handling branches to your automation workflows to store failed lead payloads in a backup database like Airtable before they hit a CRM rejection.