How to Block Unwanted Calls on iPhone and Android (2026)

Blocking one number is easy. Reducing the volume of unwanted calls is a different problem, because campaigns rotate numbers faster than you can block them. The fix is layered: device blocking for repeat offenders, screening for everything unknown, and carrier-level filtering for the traffic that never should have reached you.

Layer 1 — block a specific number

iPhone

1. 1Open the Phone app and tap Recents.
2. 2Tap the information icon next to the number.
3. 3Scroll down and choose Block this Caller, then confirm.
4. 4Manage the list later under Settings, Apps, Phone, Blocked Contacts.

Android

1. 1Open the Phone app and go to Recents.
2. 2Long-press or tap the number, then choose Block or Block / report spam.
3. 3Confirm, and tick the reporting option so the number feeds into Google's spam signals.
4. 4Review under Phone app, Settings, Blocked numbers.

Layer 2 — screen everything you do not know

This is the setting that changes your day-to-day experience. On iPhone, Settings, Apps, Phone, Silence Unknown Callers sends any number not in your contacts, recent outgoing calls or Mail straight to voicemail, still listed in Recents. On Android, Phone app, Settings, Caller ID and spam enables filtering, and on Pixel devices Call Screen answers unknown calls and shows a live transcript before you pick up.

The trade-off is real: a clinic calling from a switchboard you have never stored gets silenced too. Check voicemail and the Recents list once a day and the trade-off is manageable.

Layer 3 — carrier-level filtering

Most major carriers now run network-side filtering that never rings your phone at all, usually free at a basic tier. Ask your provider for their spam-blocking or call-protection service, and while you are there ask two more things: a bar on outgoing international and premium-rate dialling if you never need it, and confirmation that caller ID authentication is active on your line.

Layer 4 — reduce the supply of your number

• Register on your national do-not-call list. It will not stop criminal operations, but it removes legitimate telemarketing.
• Stop publishing your number on public profiles, marketplace listings and CVs where scrapers collect it.
• Untick the marketing and partner-sharing boxes at checkout — that is where most list resale originates.
• Use a secondary number for signups and deliveries and keep your primary line for people you know.

Report the worst offenders

Reporting is the only step that affects other people's phones as well as yours. In the US, file with the FTC and the FCC. In the UK, Ofcom and Action Fraud. In the EU, your national telecoms regulator. Include the number, the date and time, and what the caller asked for — enforcement work depends on those details.

The short version

Block repeat offenders, silence unknown callers, turn on carrier filtering, and stop feeding your number into lists. Together those four layers cut unwanted volume dramatically; any one of them alone does not.