Phone contact should be something your members opt into. Collect that
consent explicitly. A separate, unchecked checkbox at signup works well.
Use clear language like “I agree to receive phone calls from [Your Company]
about my account, including AI-assisted calls.” Store the consent on your
own records, together with the wording they agreed to. Give people a way to
opt out.
Where the number has to be
When a member cancels or a payment fails, hyzl reads their phone number from one specific place per provider:
hyzl does not use a number kept anywhere else. That includes a charge, an invoice, metadata, and a custom RevenueCat attribute. It normalizes numbers to E.164, and it skips anything that cannot be normalized.
Stripe
hyzl reads the Phone field on the StripeCustomer. Three ways to get it there:
- New members (automatic). Turn on phone number collection for Checkout or Payment Links. Stripe then saves the number onto the
Customerfor you. - One member. Open their
Customerin Stripe, choose Edit, and fill in the Phone field. - In bulk. Set
customer.phonein E.164 format (for example+15551234567) through the Stripe API.
RevenueCat
hyzl reads the reserved$phoneNumber subscriber attribute. Other custom attributes are not used.
- In your app. Set
$phoneNumberas soon as you have the number, after a one-time password step or at signup. Use thesetPhoneNumberhelper in the RevenueCat software development kit. - Existing members. Set the
$phoneNumberattribute through the RevenueCat subscriber attributes API. - Format. Use E.164 (for example
+15551234567). Free-text numbers are normalized where possible and skipped when they cannot be.
$phoneNumber is a reserved RevenueCat attribute, not a custom one you create.
Set it with the reserved setPhoneNumber helper (or the reserved $phoneNumber
key) so it lands in the right place.Check your coverage
Two places in the portal show how many of your members are reachable:- On the main Dashboard,
See where you're losing peopleshows a Who we can chase figure. That is the share of people who left that have a phone we can call or text. - On the Integrations page, the connected Stripe card shows your overall phone coverage.

