Use the instructions for your own iOS version if its menus differ. Apple's guide has a version-specific URL; do not assume every phone has the latest controls.
For an unknown message, Report Spam may be available below the message, followed by Delete and Report Spam. Reporting availability for SMS, MMS and RCS depends on the carrier and region. Reporting alone does not block future messages, so use the sender block separately when needed.
Save any message you need as a record before deleting it. Do not reply to a suspicious sender just to make a reporting option appear.
Open Messages and tap the Filter button in the conversation list.
Choose Manage Filtering.
Turn on Screen Unknown Senders.
Review Allow Notifications if you need alerts for categories such as verification codes. Availability varies by country and region.
Unknown messages are separated from the main list rather than treated as a complete gambling-category block. Check the Unknown Senders folder for legitimate messages. Apple's text-message filtering also has limits for senders you have already replied to; use an individual block for a known unwanted sender.
If the problem is a group conversation, use the group controls to leave or mute it where available. The individual-number block does not become a block on every new group or sender.
These steps are for Google Messages, not every Android messaging app. Google's current Android instructions give this route:
Open Google Messages.
In the conversation list, touch and hold the conversation you want to block.
Tap Block, then OK. Review any reporting choice shown by your version.
To review blocked conversations, open your profile icon > More options > Spam & blocked. Check this area if an expected message is missing. Unblocking a sender changes the restriction, so review the selected number before confirming.
If you use Samsung Messages or another app, open that app's official Help for its own block and spam controls. Menu names from Google Messages may not match.
Check Spam and Scam Protection
Google's current protection Help directs users to profile icon > Messages settings > Protection & Safety > Spam and scam protection, where available.
Review the available protection mode and its privacy explanation. This can help identify suspected spam; it is not a verified gambling-keyword filter and does not establish that every betting promotion will be caught. A message from a known operator may need a separate marketing opt-out or sender block.
If you recognize the operator and know the message is genuine, follow its marketing opt-out instructions. In Great Britain, the Gambling Commission says this commonly means sending STOP to the stated number or shortcode.
You can also open the operator's known official app or website directly and turn off SMS marketing, where offered, or ask official support to stop it. Keep the reply if the messages continue.
For an unknown or suspicious sender, avoid its links and do not send personal information. Use the messaging app's block/report controls and your carrier's official support instead of relying on a claimed unsubscribe page.
United States: the FTC's spam-text guidance lists forwarding unwanted messages to 7726 (SPAM), reporting through the messaging app, or reporting fraud through its official service. Contact your carrier if you need help forwarding or reporting.
Great Britain: the Gambling Commission also points to 7726, the mobile network and the ICO for continued unwanted marketing. Those routes have their own jurisdiction and scope.
Elsewhere: check your mobile network's official reporting process. Do not assume a US or British shortcode works in every country.
Forwarding a report is different from following a link in the original message. The FTC advises checking a supposedly genuine issue through a phone number or website you already know, rather than the contact details in the text.
Block or report that sender too; check your app and carrier filtering options
A business name appears instead of a number
Ask your carrier which controls support that type of sender
Notifications stop but messages remain
You may have muted or filtered the conversation; review whether you also need a sender block
A login code or support reply disappears
Check unknown-sender and spam folders before changing broad filters
Messages appear in WhatsApp, email or another app
Use that app's separate controls; SMS settings do not manage every communication channel
Avoid a blanket rule that hides all unknown messages without checking the effect on account access, work and essential services. You can make the settings stricter while preserving a way to review legitimate messages.