GoHighLevel + iMessage: A Setup Guide for Lead Gen Agencies

What does the iMessage (ZeroSettle) app do in GoHighLevel?

The iMessage (ZeroSettle) app makes a client's ZeroSettle number the SMS provider for one GoHighLevel sub-account, so the texts that sub-account already sends go out over iMessage from that number. ZeroSettle runs the number on Apple hardware we operate for you in a server facility, and nothing in GoHighLevel has to be rebuilt.

• Sending. Texts from the conversations inbox, the mobile app, workflow Send SMS actions and bulk actions are sent from the client's number. Each is marked delivered or failed, with the reason.
• Logging. Replies, and texts the number sends from the ZeroSettle API, the console or the hosted AI agent, show up in the contact's conversation. A number the sub-account doesn't have yet gets a new contact, unless you turn that off. Photos, videos and voice messages show as [photo], [video] and [voice message].
• LeadConnector. LeadConnector is HighLevel's white-label brand. It is the same app, with the same setup and behavior; only the install page differs.

GoHighLevel records these as SMS; the person on the other end sends and receives iMessages.

How should an agency set up numbers across client sub-accounts?

Give each client sub-account its own ZeroSettle account and number, and add numbers to a client only when its campaigns need more first texts a day. Three facts from the docs push you there:

• One account per sub-account. A sub-account connects to one ZeroSettle account: installing it for a second account comes back with an error until the first disconnects or no longer has a paid number.
• The lead sees the client, not the agency. Set each account's App/Brand Name and photo to the client's business.
• Limits and opt-outs stay separate. Each number has its own daily new-contact allowance, and a STOP blocks every number on the account, so one client's opt-outs never touch another's.

Each account signs in with a phone number. On Growth the owner can invite team members, so a client that owns its account can bring the agency in to work on it. How many numbers a client needs depends on how many conversations it starts each day: a med spa whose leads mostly tap a "Text us" button needs few new-contact slots, while a home service client texting every lead-ad form fill needs more. For a client-side view of the same playbook, see iMessage for lead generation and real estate lead follow-up over iMessage.

How do you connect a client sub-account?

Connecting takes a ZeroSettle number for the client, one OAuth approval on the client's sub-account, and one setting in GoHighLevel. Plan on these steps for each client:

1. Get the client's number. Pro is self-serve at portal.zerosettle.io/imessage, and a Pro account can upgrade to Growth in the console; a Growth link starts on Growth with 3 numbers. Sign in with a phone number (a one-time SMS code), answer the use-case question, set the client's brand name and photo, and subscribe. Numbers not paid for within 30 minutes are released.
2. Decide who answers. In the console's Messaging tab, under Who answers, choose Managed by API if GoHighLevel workflows and staff will send. A new signup starts Managed by AI Agent, and a number managed by the AI agent only sends through the agent, so GoHighLevel's sends from it are marked failed. (More on this choice below.)
3. Start the connection. In the ZeroSettle console, open Settings → CRM → GoHighLevel (or LeadConnector) and choose Connect with GoHighLevel.
4. Pick the client's sub-account and approve the app. Install it on the sub-account, not the agency: an agency-level install comes back with an error.
5. Switch the SMS provider. In GoHighLevel, open Settings → Phone Numbers → Advanced Settings → SMS Provider, choose iMessage (ZeroSettle) and save.
6. Test it. From your own iPhone, text the client's number. The text should appear as an incoming SMS in a contact's conversation. Reply from the GoHighLevel inbox and check that it is marked delivered.

Onboarding many clients? Your tooling can start the install with the client's API key ("brand": "leadconnector" for white label), then open the returned authorize_url in a browser signed in to GoHighLevel.

BASE=https://portal.zerosettle.io   # TOKEN is the client account's API key
curl -s -X POST -H "Authorization: Bearer $TOKEN" -H 'Content-Type: application/json' \
  -d '{"brand":"gohighlevel"}' $BASE/api/imessage/integrations/gohighlevel/oauth
# {"authorize_url": "https://marketplace.leadconnectorhq.com/oauth/chooselocation?…"}

Two settings, through PATCH /api/imessage/integrations/gohighlevel:

• create_contacts: false logs only messages with numbers the sub-account already has, useful if the number also gets vendor texts you don't want in the CRM.
• line_id: with several numbers, the one GoHighLevel sends from. null sends from the number the conversation is already on.

GET /api/imessage/integrations/gohighlevel returns the connection: the sub-account's location_name, last_synced_at, last_error and pending (writes still waiting on GoHighLevel, such as messages to log and send statuses to report). POST /api/imessage/integrations/gohighlevel/check rechecks the connection. Full reference: CRM integrations.

How do you build a speed-to-lead workflow that stays within the limits?

Send one plain-text message the moment the form arrives, ask one easy question, and let the lead's reply open the conversation. Your form or lead-ad trigger and a Send SMS action do the work.

That first text is a new contact, because the number starts the conversation: 5 a day on Pro; 50 per number on Growth, at most 3 every 15 minutes (the day resets at 3 AM Eastern). Write it to the iMessage rules:

• Say who you are and what they asked for. "It's Marco at Brightline Painting, about the exterior estimate you just requested" beats a generic greeting.
• No link. A link to someone who has never texted the number shows as plain text they can't tap; send it after they reply (see why first-message links aren't tappable).
• No photo, video or voice message. ZeroSettle refuses them to a contact who has never replied.
• End on a question they can answer in a word: one story or two, this week or next, a time of day.

Campaign spikes. On Growth, a number opens at most 3 new conversations in any 15 minutes, so if an ad brings ten form fills in ten minutes, three get texted and the rest are marked failed with the new-contact limit; call those leads. To raise the ceiling, add numbers (each has its own allowance), or put a "Text us now" button with a pre-filled sms: link on the thank-you page: people who text first never count as new contacts, their links are tappable from the start, and their conversation stays out of the Screen Unknown Senders list that iOS 26 uses for texts from unknown senders. How to get customers to text you first shows the link format, and texting lead ad leads in seconds and speed to lead for home service businesses go deeper on the first minutes.

How should follow-up sequences change on iMessage?

Cap every sequence at two texts before the lead's first reply, then hand non-responders to calls or email. ZeroSettle allows at most 2 messages to a contact who has never sent the number anything; a third is refused with 403 awaiting_reply and marked failed in GoHighLevel. Messages sent within 5 minutes of the first count as one, and once the lead sends anything back (a text, photo, voice note or tapback), that rule is gone for that contact.

A second text that works: "Hi Tasha, Marco again from Brightline. Happy to price the trim only if that's easier. Want a couple of times?"

In the docs' words, "Repeated messages to people who never answer are the fastest way to get a number flagged by Apple: when that happens every send fails, to everyone." Keep promotional texts between 8 AM and 9 PM in the recipient's time zone. More patterns are in lead nurture on iMessage without getting your number flagged and what happens if your number is flagged.

Can you use bulk actions with an iMessage number?

Yes, and they work best for contacts who already have a conversation with the client's number. Every recipient of a bulk action goes through the same rules as a single send, so the result depends on who is on the list:

So a bulk "spring special" to 400 past customers on a brand-new number is mostly new contacts: only 5 (Pro) or 50 per number (Growth) go each day, and on Growth no more than 3 in any 15 minutes, so a batch of 50 takes more than four hours to go out. Split the list into daily batches, space the sends out, and send only to customers who agreed to texts from the business. Bringing back past painting customers walks through a reactivation that respects the cap. Never load a purchased or scraped list into a sub-account and blast it.

Should GoHighLevel or the hosted AI agent run the conversation?

Let GoHighLevel run it when the client's staff or your workflows reply; let ZeroSettle's hosted AI agent run it when the client wants every text answered at once without staff. The choice is per sender (a name and photo and its numbers), and it is either-or.

With the agent, GoHighLevel becomes the record: the client sees every text in the contact's conversation while the agent answers. The agent knows only its business context and any files you connect (it can also use tools from MCP servers you add), follows the same rules (STOP, the new-contact limits, at most 2 texts before a first reply), and by default follows up once, the morning after a lead goes quiet. The setup is in AI agent in the console; qualifying leads with an AI agent shows how to brief it, and how the hosted agent works covers its settings.

Why would a GoHighLevel send be marked failed?

A GoHighLevel send is marked failed when one of ZeroSettle's sending rules refuses it, and the failure carries the reason. Sends from GoHighLevel follow the same rules as POST /api/imessage/send:

If nothing is being logged or sent at all, look at last_error and pending in the integration status, and recheck the connection with POST /api/imessage/integrations/gohighlevel/check. If every send fails, to everyone, the number may have been flagged by Apple: see what happens if your number is flagged. The full code table is in Errors, limits, and compliance.

One more gap: iMessage reaches Apple devices, and SMS fallback is a limited pilot ZeroSettle must enable per account, so keep a call or email step for leads who never reply.

What consent do you need before texting leads?

Text only people who gave the client their number for this purpose, and keep the record. That means an estimate or quote request, a web form or lead-ad form whose consent language covers texts from the business, a past customer who agreed to texts, or someone who texted the number first. It never means purchased lists, scraped numbers, door-knock sheets or cold texting. As the docs say, "If you are unsure whether you have consent, you don't." ZeroSettle suspends lines used for unsolicited messaging.

• The law. In the United States, the FCC's rules generally require prior express written consent for advertising or telemarketing covered by the autodialer rules, and do-not-call and state laws may apply too. Other countries have their own rules. Read iMessage marketing and TCPA consent; this is not legal advice.
• Say who you are in the first text, using the client's business name.
• STOP is enforced for you. When a contact texts STOP (or a phrase such as "remove me" or "wrong number"), ZeroSettle blocks every number on the account from reaching them, and any GoHighLevel send to them is marked failed. The STOP itself still lands in the contact's conversation. CANCEL and END are not recognized as opt-outs, so treat them as opt-outs yourself in GoHighLevel.
• Lead-ad forms: the consent language should name texting by the client's business, and each client should hold its own consent records.

What does it cost an agency per client?

A client's single number costs $49 a month on Pro, Growth is $199 a month per number (or $599 a month for 3 numbers from a Growth link), and Enterprise pricing is custom, through sales. Pick the plan by how many conversations the client starts each day:

Every number allows 10,000 messages a day, sent and received, with known contacts. Subscriptions carry a 30-day money-back guarantee.

Credits pay only for the hosted AI agent's texts (one per text it sends) and for videos; free credits come once per account and never refill, and packs (1,000 for $50 or 5,000 for $200) never expire. A client whose staff answer from GoHighLevel uses no credits for texts. Full details are in ZeroSettle pricing and the Your iMessage number docs. To set up the first client, get a number and connect its sub-account.