iPhone
- Open Phone → Recents, tap the ⓘ next to the number and choose Block this Caller.
- Turn on Settings → Phone → Silence Unknown Callers. Calls from numbers that aren’t in your contacts go straight to voicemail.
- Under Settings → Phone → Call Blocking & Identification, turn on any spam-blocking apps you trust.
Android
- Open the Phone app, go to Recents, long-press the number and tap Block / report spam.
- In Settings → Caller ID & spam, turn on Filter spam calls.
Block many numbers at once
Every number page has a link to download our spam blocklist as a vCard. Import it into your contacts, then block the single “Spam” contact. That blocks every number on the list.
Carrier tools
Most US and Canadian carriers offer free spam-call filtering. Search your carrier’s app for “call filter” or “scam shield”. Also register your number on the National Do Not Call Registry (donotcall.gov) or, in Canada, the National DNCL (lnnte-dncl.gc.ca).