Guides
How to check if a number is on WhatsApp without saving it as a contact
Three free ways to check if a number is on WhatsApp without adding a contact, what the wa.me 'invalid' message means, and how to format numbers by country.
11 min read
Articles tagged “Consent”
11 articles.
Guides
How to fix a low Meta Custom Audience match rate on a phone list
Why phone lists match poorly in Meta Custom Audiences: missing country codes, dead and recycled numbers, landlines. The format Meta expects and a cleanup order.
11 min read
Guides
The TCPA "revoke-all" opt-out rule: what the FCC's 2026 order changes
What the TCPA revoke-all opt-out rule required, why it was delayed to 31 January 2027, how the FCC's September 2026 order (FCC 26-67) replaces it, and an opt-out data model. Not legal advice.
11 min read
Guides
Is it legal to check if a number is on WhatsApp? Consent and data-protection rules for businesses (2026)
Is a WhatsApp number check legal? GDPR, India's DPDP Act, Brazil's LGPD, Malaysia's PDPA and US rules, and why registration is not permission to message.
10 min read
Guides
Signal number checks: what's possible, and what isn't
A Signal number lookup can only say whether a findable Signal account uses a number you hold, never whose it is. What the check sees and when not to use it.
7 min read
Guides
TCPA compliance checklist for SMS senders (2026)
A dated TCPA checklist for SMS: consent, opt-out words, 10-day revocation, quiet hours, do-not-call, reassigned numbers and list hygiene. Not legal advice.
9 min read
Guides
How to check if a phone number uses iMessage
To check if a number uses iMessage, run a bulk iMessage check (yes, no or unknown). Find your own iMessage ID in Settings, plus blue vs green bubbles and RCS.
7 min read
Guides
Messaging-app registration checks: a guide for every app
What a registration check tells you for WhatsApp, Telegram, Viber, Signal, iMessage, RCS, LINE, Zalo and more: modes, unknowns, billing and consent.
9 min read
Guides
Telegram number check: a practical guide to what it can and can't tell you
How Telegram's phone and username model differs, what a registration check can and can't tell you, how privacy settings affect it, with API examples.
7 min read
Guides
WhatsApp Business account check: what the business flag tells you (and what it doesn't)
To tell if a WhatsApp number is a business account, open its profile (business details, blue check for official accounts) or run a business check in bulk.
8 min read
Developers
How to check if a phone number is on WhatsApp with an API
How a WhatsApp registration check works, what registered, not registered and unknown mean, and how to call it responsibly from cURL, Node and Python.
9 min read
