Let customers text the founder from your cancel flow, over iMessage

Who uses iMessage for cancel-flow saves?

Founder-run SaaS products, subscription apps and membership businesses with a self-serve cancel flow use a “Text the founder” step to hear why a customer is leaving while the problem can still be fixed. ZeroSettle is an iMessage API: a real phone number on real iMessage, running on Apple hardware we operate for you, that your code texts customers from and hears back on through a bearer token and signed webhooks.

A cancel survey’s checkbox (“Something isn’t working”) arrives after the customer has gone, and nobody can ask what broke. A thread from the cancel screen gets the specific answer while a fix, a pause, a downgrade or a refund is still possible. See when it is not a fit, or other iMessage use cases.

How iMessage for cancel-flow saves works, step by step

The customer starts the conversation, not your server: an optional button opens Messages with a reference prefilled, ZeroSettle posts the text to your webhook, and the founder answers in the same thread.

1. An optional “Text the founder: we’ll fix it or refund you” button sits beside a Cancel button that works without texting.
2. Your server stores a short reference for the cancel attempt, and the button is an sms: link to your number with “Cancel ref 8812” prefilled.
3. The customer taps Send. About 1–2 seconds after the line receives the text, ZeroSettle posts a signed message.received event to your webhook.
4. Your webhook ties the reference to the account and posts it to the founder in Slack through a relay you build. The thread is also live in the ZeroSettle console.
5. The founder replies from the console or a Slack slash command that calls POST /api/imessage/send: a quick fix, a pause, a downgrade or a refund, applied in billing first.
6. A voice note from the founder can follow through the same endpoint as audio_b64, arriving as Messages’ native audio bubble.
7. If the customer still wants to leave, the founder cancels at once.

The other path: one save offer to opted-in users

Users who already opted in to texts can get one save offer from your backend instead: “Before you go: 2 months free if you stay. Reply YES.” It is the cancel-flow trigger in ZeroSettle’s retention offers docs, on the same backend that recovers paywall abandonment, with the same rules: one offer per user per week, the two free months created in billing before the text goes out, and no link until they reply. Because your server sends it first, quiet hours apply, and it counts as a new contact if you have never texted each other.

Example conversation: cancel-flow saves

In this thread a customer taps “Text the founder” on the cancel screen of Tidyslot, a fictional scheduling app, and the founder fixes the problem instead of cancelling.

Behind it, the relay put the 👍 on Dana’s first text the moment it arrived, ref 8812 resolved to her account and last week’s sync error, and the free month was applied in billing before Ravi mentioned it.

Setup: a prefilled sms: button and a reference lookup

Setup is three small pieces, following the customer support section of the ZeroSettle docs: the button, a reference lookup in your webhook, and a send call for a voice note.

The button

The button is a plain sms: link beside a Cancel form that works on its own (more in getting customers to text you first).

<a class="btn" href="sms:+18055550100&body=Cancel%20ref%208812">Text the founder: we'll fix it or refund you</a>
<form method="post" action="/billing/cancel"><button>Cancel subscription</button></form>

Keep the reference short, opaque and expiring; never an email, account ID or token, since the customer sees it. On an iPhone the link opens Messages; on Android it opens the SMS app, and ZeroSettle has no SMS fallback, so put an email or chat link beside it for those customers.

The webhook: tie the reference to the account

Start from the docs’ Slack relay, which verifies X-ZeroSettle-Signature, dedupes retries and adds the /imsg reply command (see routing iMessage support to Slack and how ZeroSettle webhooks work). The relay also puts a 👍 tapback on each text so the customer knows it landed. In its message.received branch, send this function’s output to Slack in place of the relay’s own text:

import re
REF = re.compile(r"\bcancel ref (\d{4,6})\b", re.I)

def cancel_context(m: dict) -> str:
    text = m.get("text") or ""
    found = REF.search(text)
    # your DB: try the reference, then fall back to the sender's number
    acct = (found and accounts.by_cancel_ref(found.group(1))) or accounts.by_phone(m["handle"])
    flag = "number on file" if acct and acct.phone == m["handle"] else "CHECK IDENTITY"
    who = acct.name if acct else "Unknown customer"
    return f"*Cancel flow* {who} ({flag}):\n> {text}\n_reply with_ `/imsg {m['handle']} your answer`"

A reference is a lookup, not proof of identity: before a refund or plan change, check the flag or confirm by email.

The founder’s voice note

A voice note is one POST /api/imessage/send with audio_b64; this is the docs’ Python helper:

import base64, os, requests
BASE = "https://portal.zerosettle.io"
TOKEN = os.environ["ZEROSETTLE_TOKEN"]   # your API token, never in source

def send_voice(to: str, path: str) -> dict:
    with open(path, "rb") as f:
        audio = base64.b64encode(f.read()).decode()
    r = requests.post(f"{BASE}/api/imessage/send",
                      headers={"Authorization": f"Bearer {TOKEN}"},
                      json={"to": to, "audio_b64": audio, "audio_format": path.rsplit(".", 1)[-1]},
                      timeout=120)
    return r.json()

send_voice("+18055559876", "founder-note.m4a")

Voice notes go through the API (the console sends texts and photos): up to 6 MB of m4a, mp3, wav, aiff, caf, flac, aac, mp4 or amr, which ZeroSettle converts. The call returns once the line has handed the note to Apple, a few seconds longer than a text. A voice bubble has no caption, so send words as a second message.

Limits and consent for cancel-flow saves

A conversation the customer starts from the cancel screen never counts against ZeroSettle’s new-contact limit, so Pro’s 5-a-day cap matters only for save offers your backend sends first. On consent, the customer chooses to text, and cancelling must never depend on it.

Source: ZeroSettle API docs, “Errors, limits, and compliance”. The day runs 3 AM to 3 AM Eastern.

The limit math

Take a product on Pro with 15 cancel attempts a week. Button texts never count, and a “Before you go” offer to each opted-in canceller you have never texted adds about 2 new contacts a day, under Pro’s 5. A price-change spike of 30 cancels in one day is different: the 6th offer that day returns 429 new_contact_limit with retry_after_s and would wait for the 3 AM Eastern reset. By then the customer has left and quiet hours rule out the text, so drop offers that can’t go out within minutes instead of queueing them overnight.

• Save offers likely need consent: send them only to users who gave you their number for texts, and only between 8 am and 9 pm in their time zone.
• “Stop charging me” is an opt-out. Any text with the word STOP in it, or a clear request like “take me off your list”, blocks every number on your account from reaching that person until they text START (403 recipient_opted_out), so the founder can’t reply in the thread: cancel and confirm by email. See how STOP works.

When ZeroSettle is not a fit for cancel-flow saves

A “Text the founder” step is the wrong tool when it slows cancelling, when no one can answer, or when customers can’t receive iMessage.

• You’d block cancellation behind the conversation. Required texting turns help into an obstacle.
• Nobody can answer quickly. A customer on the cancel screen waits minutes, not a day; show the button only when someone is on.
• Most users are on Android. There is no SMS fallback; keep email or in-app chat for them.
• You want a fully automated save bot. On lines the hosted AI agent (Beta) manages, inbound texts skip your webhook and your own sends are refused, so put the agent on a separate number or call your own model from the webhook. See hosted-agent win-backs.
• Subscriptions are billed through the App Store. Customers cancel in their Apple subscription settings and request refunds from Apple, not from you, so don’t promise a cancellation or refund the thread can’t deliver.

How much does iMessage for cancel-flow saves cost?

Cancel-flow saves cost the ZeroSettle plan price and nothing per message: Pro is $49 a month, starting with one number, and Growth is from $599/mo for several numbers working as one. Messages are unlimited; only new contacts are capped.

See plans or the pricing explainer, read the API docs, or get a number.