How to cut down spam calls and robocalls

Most people can dramatically reduce unwanted calls using tools they already have. Nothing here needs a paid app or a subscription.

On iPhone

• Settings → Apps → Phone → Silence Unknown Callers. Calls from numbers not in your contacts, mail, or messages go straight to voicemail.
• Settings → Phone → Call Blocking & Identification, then enable any silence/identify options your carrier provides.
• Block individual numbers from the recent-calls list via the ⓘ icon → Block this Caller.

On Android

• Phone app → ⋮ → Settings → Spam and Call Screen → turn on "See caller and spam ID" and "Filter spam calls".
• On Pixel devices, Call Screen can answer and screen unknown calls for you.
• Block a number from Recents → long-press → Block / report spam.

Beyond your handset

Register on your national do-not-call list (donotcall.gov in the US, the TPS in the UK). It will not stop criminals, who ignore the list, but it does cut legitimate telemarketing. Your mobile carrier also usually offers free network-level spam filtering — check its app or account settings.

One habit matters more than any setting: do not engage. Answering, pressing a key, or saying anything confirms the number is live and increases the volume of calls. Let unknown numbers go to voicemail.