GoHighLevel + iMessage: How to Connect HighLevel to senderZ

GoHighLevel is where agencies manage their client communications — pipelines, automations, appointment scheduling, and outreach. But HighLevel’s native SMS channel routes through traditional carriers, which means carrier filtering, 10DLC registration headaches, and no iMessage support.

senderZ connects to GoHighLevel and adds iMessage as a messaging channel. When a HighLevel workflow triggers a message, senderZ delivers it via iMessage when the recipient supports it and falls back to SMS automatically. Your HighLevel automations keep working exactly as they do now — the only difference is that Apple device users receive an iMessage instead of a carrier SMS.

This guide covers how to connect HighLevel to senderZ, how subaccount mapping works for agencies, which automation triggers to use, and real-world use cases like appointment reminders and review requests.

Why iMessage in HighLevel

HighLevel’s built-in SMS works. But agencies running client campaigns see three recurring problems:

Carrier filtering. A2P SMS (application-to-person) messages pass through carrier filtering systems. Promotional messages, appointment reminders, and review requests are frequently flagged — especially from 10DLC numbers that have not been fully registered and warmed. Messages that get filtered never arrive. The recipient never knows.

No read receipts. SMS does not support read receipts. When you send an appointment reminder, you have no way of knowing whether the recipient actually saw it. You only know it was “delivered” to the carrier — not to the person.

10DLC registration. The 10DLC (10-digit long code) registration process requires brand registration, campaign registration, carrier approval, and ongoing compliance monitoring. For agencies managing 20 or 50 subaccounts, this is a significant operational burden. Each subaccount needs its own registration.

iMessage addresses all three. Messages bypass carrier filtering entirely because they go through Apple’s infrastructure, not the PSTN. Read receipts tell you whether the message was seen. And there is no 10DLC registration for iMessage — it works immediately.

For more on how senderZ handles message routing, see the quickstart documentation.

How the Integration Works

The senderZ HighLevel integration uses OAuth to connect your HighLevel account to your senderZ tenant. Once connected, senderZ appears as a messaging channel in HighLevel workflows.

The architecture:

HighLevel Workflow → Trigger fires → senderZ webhook receives event
→ senderZ API routes message → iMessage or SMS delivered
→ Delivery status sent back to HighLevel via timeline event

Messages flow one direction (HighLevel triggers the send, senderZ delivers), and status updates flow back so your HighLevel timeline stays accurate.

Inbound replies work too. When a recipient replies to an iMessage or SMS sent through senderZ, the reply is forwarded back to HighLevel and appears in the contact’s conversation timeline.

Step 1: Connect Your HighLevel Account

Navigate to the senderZ integrations page in your portal and select GoHighLevel. Click “Connect” to start the OAuth flow.

Using the API directly

If you prefer to connect programmatically:

curl -X POST https://api.senderz.com/v1/integrations/highlevel/connect \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "redirect_uri": "https://your-app.com/callback",
    "scopes": ["contacts.read", "contacts.write", "workflows.read"]
  }'

The response includes an authorization_url. Redirect the user (or yourself) to this URL to complete the OAuth flow in HighLevel. After authorization, senderZ receives an access token and stores it encrypted (AES-256-GCM) in your tenant’s integration record.

Using TypeScript

import { SenderZ } from "@senderz/sdk";

const client = new SenderZ({ apiKey: "YOUR_API_KEY" });

const connection = await client.integrations.connect("highlevel", {
  redirect_uri: "https://your-app.com/callback",
  scopes: ["contacts.read", "contacts.write", "workflows.read"],
});

// Redirect user to connection.authorization_url

Step 2: Map Subaccounts (Agencies)

If you run an agency with multiple HighLevel subaccounts, senderZ maps each subaccount to a separate senderZ tenant. This ensures complete data isolation — Client A’s messages and contacts are never visible to Client B.

The mapping happens automatically during the OAuth flow if you authorize at the agency level. senderZ creates a tenant for each subaccount and associates the appropriate phone numbers.

For manual mapping:

curl -X POST https://api.senderz.com/v1/integrations/highlevel/map-subaccount \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "highlevel_subaccount_id": "sub_abc123",
    "senderz_tenant_id": "tenant_xyz789"
  }'

Each subaccount can have its own dedicated phone number (Growth and Scale plans) or share from the pooled number pool (Starter plan). For details on phone number options, see the pricing page.

For full details on the agency multi-tenant setup, see the Agency OS product page.

Step 3: Configure Automation Triggers

With the integration connected, you can trigger senderZ messages from any HighLevel workflow. The integration supports these trigger types:

Contact events:

• Contact created
• Contact tag added
• Contact moved to pipeline stage
• Contact appointment scheduled
• Contact appointment reminder (configurable time before)

Workflow actions:

• Send message via senderZ (custom body)
• Send message via senderZ (template)
• Check iMessage capability
• Log delivery status to timeline

Example: Appointment Reminder Workflow

Here is a HighLevel workflow that sends an appointment reminder 2 hours before a scheduled appointment:

1. Trigger: Appointment reminder (2 hours before)
2. Action: Send message via senderZ
3. Template: appointment_reminder
4. Variables: {{contact.first_name}}, {{appointment.start_time}}, {{appointment.location}}

The resulting message:

Hi Sarah, this is a reminder about your appointment tomorrow at 2:00 PM at 123 Main St. Reply YES to confirm or call us to reschedule.

Because senderZ routes via iMessage when possible, this message arrives in the recipient’s iMessage inbox — not in an SMS thread that might get filtered or buried.

Example: Review Request After Service

1. Trigger: Contact tag added (“service-completed”)
2. Wait: 2 hours
3. Action: Send message via senderZ
4. Body: "Hi {{contact.first_name}}, thanks for visiting us today! If you have a moment, we'd appreciate a review: {{review_link}}"

Review requests sent via iMessage have significantly higher engagement than SMS because iMessage links render with rich previews — the recipient sees the review site’s name and icon before tapping.

Step 4: Handle Inbound Replies

When a recipient replies to a senderZ message, the reply is forwarded to HighLevel through the integration webhook. The reply appears in the contact’s conversation timeline, and you can use it as a trigger for further automation.

To receive inbound messages, senderZ sends a webhook to your registered endpoint:

curl -X POST https://api.senderz.com/v1/integrations/highlevel/webhook \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "event": "message.received",
    "highlevel_location_id": "loc_abc123"
  }'

Inbound messages include the sender’s phone number, the message body, and the channel (iMessage or SMS). HighLevel workflows can trigger on these inbound events — for example, routing a reply to a specific team member or updating a pipeline stage.

For more details on webhook configuration, see the customer support solutions page.

Use Cases for Agencies

Dental and Medical Practices

Appointment reminders are the primary use case. A dental office using HighLevel can send reminders via iMessage, get read receipts confirming the patient saw the reminder, and reduce no-shows. If the patient replies “YES” to confirm, the reply appears in HighLevel and can trigger an automated confirmation update.

Real Estate Agents

Property showing confirmations, open house invitations, and follow-up messages after showings. iMessage link previews make property photos visible directly in the message thread — a significant upgrade from plain SMS links.

Home Services

Service confirmation messages, technician ETA updates, and post-service review requests. The two-way messaging capability lets customers reply with questions or reschedule requests that route directly to the HighLevel conversation.

Fitness and Wellness

Class reminders, membership renewal notices, and promotional offers for new classes. Quiet hours enforcement (built into senderZ) ensures promotional messages are never sent between 8 PM and 8 AM local time, keeping your business compliant without manual scheduling.

Monitoring and Troubleshooting

The senderZ portal shows delivery status for every message sent through the HighLevel integration. You can filter by:

• Subaccount (for agencies)
• Date range
• Channel (iMessage vs SMS)
• Delivery status (delivered, failed, pending)

If a message fails, the portal shows the failure reason and whether a fallback was attempted. Common issues:

• Invalid phone number format: HighLevel stores numbers in various formats. senderZ normalizes them to E.164 automatically, but malformed numbers (missing country code, extra characters) will fail.
• Opt-out: If the recipient previously texted STOP, the message is blocked by senderZ’s compliance system. The contact’s opt-out status is visible in the portal.
• Rate limit: Each plan has a daily new-contact limit. If the limit is reached, additional messages to new contacts are queued until the next day.

Frequently Asked Questions

Do I need to register for 10DLC to use senderZ with HighLevel?

No. senderZ routes messages through iMessage when the recipient supports it, which does not require 10DLC registration. For SMS fallback to non-Apple devices, senderZ handles carrier compliance on its end. You do not need to register a brand or campaign with carriers.

Can I keep using HighLevel’s built-in SMS alongside senderZ?

Yes. The senderZ integration adds a new messaging channel — it does not replace HighLevel’s existing SMS. You can choose which channel to use per workflow, or use senderZ for all messaging and disable the built-in SMS.

How does subaccount billing work for agencies?

Each HighLevel subaccount maps to a senderZ tenant with its own plan and billing. Agencies can manage all tenant subscriptions from a single senderZ dashboard. Volume discounts are available for agencies managing 10 or more subaccounts — contact sales through the pricing page.

Will replies appear in the HighLevel conversation timeline?

Yes. Inbound replies are forwarded to HighLevel in real time and appear in the contact’s conversation thread. The reply includes the channel (iMessage or SMS) and the full message body. HighLevel workflows can trigger on these inbound events.

What happens if the recipient does not have iMessage?

senderZ automatically falls back to SMS. The HighLevel workflow does not need any conditional logic — the fallback is transparent. The delivery status in both senderZ and HighLevel will show the actual channel used (iMessage or SMS).

Ready to add iMessage to your HighLevel workflows? Connect your account at senderZ.com, follow the OAuth setup, and start sending your first iMessage-powered automation in under 10 minutes.

For the full integration reference, see the HighLevel integration page. For agency-specific features, visit Agency OS.