How to stop spam calls on iPhone

Step 1 — Silence Unknown Callers (2 min, free)

Open Settings → Phone → Silence Unknown Callers. Toggle the switch on. Any call from a number not in your contacts, not in your recent outgoing calls, and not in your Mail will go straight to voicemail without ringing.

This is the single most effective free thing you can do on iOS. The vast majority of spam callers don't leave voicemails.

Downside: legitimate unknown callers (a new doctor's office, a recruiter, a delivery driver) also get silenced. Check voicemail regularly.

Step 2 — Carrier spam filter (3 min, free)

All four major US carriers offer a free spam-blocking app that filters at the network level — more effective than on-device filtering because the call never reaches your phone.

• • AT&T: Install “AT&T ActiveArmor” from the App Store
• • Verizon: Install “Call Filter”
• • T-Mobile: Install “Scam Shield”
• • US Mobile / Mint / other MVNOs: They typically use Hiya integration — pre-installed labels work out of the box

All four offer paid premium tiers ($3-7/mo) that add reverse lookup and finer-grained control. The free tier is usually enough.

Step 3 — Register on the FTC Do Not Call list (1 min, free)

Submit your number at donotcall.gov/register. Legitimate telemarketers are legally required to remove you within 31 days. This won't stop illegal robocallers (they're already breaking the law), but it cuts out the lawful end.

Step 4 — Optional: add a screening app

If steps 1-3 still leave you with too many interruptions, or if you need legitimate unknown callers to be able to reach you (delivery drivers, new doctor offices, prospective clients), the next layer is an active screening app.

Active screening means an app or service answers the unknown call on your behalf, asks the caller who's calling and why, and only forwards through the calls that meet your rules. Robocallers can't answer the question; legitimate callers can.

See our full review of the best call-screening tools for our top pick.

The realistic outcome

Steps 1-3 alone, properly configured, eliminate ~70% of spam-call interruption within 30 days. Adding step 4 gets you to near-zero interruption — the calls still happen, you just don't hear the ring and don't need to check voicemail for legitimate callers (they're actively screened and routed).