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Quick answer

Check whether the iPhone has cellular service and whether the issue affects all numbers or only one. If service is missing, reconnect with Airplane Mode and check the carrier. If calls arrive silently, review Focus and call-handling settings. Test after one change and avoid resetting the phone as an opening step.

Choose the check that matches your symptom

Start with the row that describes what you see. You do not need to try every step.

Match your symptom to the relevant check
What you noticeWhere to start
The screen shows SOS, No Service or SearchingStart with cellular service and the active line.
Incoming calls are missed while service worksReview the affected caller and relevant call-handling settings.
Service or calling changed after activation or a line changeAsk the carrier to check the line and provisioning.
Calls work outside but fail indoorsCompare coverage and try supported Wi-Fi Calling before buying equipment.

Before you start

  • Note the iPhone model, carrier, whether the problem affects incoming calls, outgoing calls or both, and any Call Failed, SOS or No Service label.
  • If this is an urgent safety situation, use another available phone or an appropriate emergency service route instead of spending time on these checks.
  • Do not share your telephone number, IMEI, SIM identifiers or account PIN in a public chat.

Why this happens

The Wi-Fi symbol does not by itself confirm cellular calling works. Carrier provisioning, coverage, a disabled line and call-handling settings can produce different symptoms. The call’s exact behavior is more useful than a broad “phone not working” description.

What to do, step by step

Try one step at a time. Stop when the issue is resolved. If an instruction doesn't match your device, use the official model-specific guidance instead.

1

Separate a service problem from a silent call

  1. Look at the cellular status.
  2. If you see SOS, No Service or Searching, follow the service checks below.
  3. If calls reach voicemail or appear as missed calls while other calls work, focus on the affected caller and call-handling settings.
Do not call an emergency number to test the phone. Use a trusted person who agrees to one test.
2

Reconnect with Airplane Mode

  1. Open Settings, turn on Airplane Mode, wait at least 15 seconds, then turn it off.
  2. Wait for cellular service and try one ordinary call.
This briefly disconnects the phone. Do not do it during an active call or when you need immediate connectivity.
Illustrative iPhone Settings screen highlighting Airplane Mode, with no number or personal account shown.View larger
Original AI-generated UI example; menus may differ. Compare the labels with your device before continuing.
3

Check the selected cellular line

  1. For an iPhone with more than one line, open Settings > Cellular and select the line you expect to use.
  2. Check whether it is turned on.
  3. If the line is missing, ask the carrier about provisioning.
Do not delete an eSIM, reset the phone or change roaming settings just to test calling.
4

Check silent or redirected incoming calls

  1. If service works but incoming calls are missed, review Settings > Focus for an active Focus.
  2. Then review Phone settings for blocked contacts or forwarding.
  3. Recent iOS releases place Phone under Settings > Apps.
  4. Change only the setting that explains your symptom.
Unknown-caller screening labels vary by iOS version. Do not disable all call protection without first identifying the affected number.
iPhone Settings Focus page with the Do Not Disturb row highlighted for inspection.View larger
Original AI-generated UI example, not a captured screenshot. Review the Focus that could explain missed calls; change only the setting relevant to your symptom. Menus and appearance may vary.
5

Check carrier status and updates

  1. Ask the carrier whether there is an outage, account restriction or activation issue.
  2. With Wi-Fi available, open Settings > General > About and follow a carrier-update prompt if one appears.
Only the carrier can fix account provisioning or a network-side block. TechTweety cannot remove one.
6

Retest before any reset

  1. After one relevant change, retry with a trusted contact and note the result.
  2. If the issue persists, share the error label, affected directions and steps already tried with the carrier or Apple.
Reset Network Settings removes saved network information. Keep it for a documented later step after you understand what must be restored.
7

If calls work outside but fail indoors

  1. In a safe outdoor location, try one ordinary call with a trusted contact. Compare it with the same test indoors. Do not use an emergency number for testing.
  2. If calls work outside but not inside, connect to a working Wi-Fi network. Confirm your carrier supports Wi-Fi Calling for your line.
  3. Open Settings > Cellular. If you have multiple SIMs, select the line you use for calls.
  4. Choose Wi-Fi Calling, turn on Wi-Fi Calling on This iPhone, then tap Enable. Enter or confirm an emergency address only in the carrier’s setup screen if requested.
  5. Try another ordinary call indoors. If Wi-Fi Calling is unavailable, ask the carrier about supported indoor coverage options. A booster is an optional installation project only if usable outdoor cellular signal is present.
If calls fail outside too, return to the carrier checks in step 5. Do not buy a booster for a missing SIM, inactive line, outage or calls redirected to voicemail.

Still not working? Know when to stop

Stop if there is liquid damage, unusual heat, swelling or a hardware warning. Use the carrier for a missing line, outage or account block. If the carrier confirms service is correct but calling still fails, use Apple’s official support; do not buy a replacement phone based only on a failed call.

Write down the exact model and error message before contacting official support.

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Still seeing the same problem?

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OPTIONAL, NOT A REQUIREMENT

Useful tools, only if they fit your situation

Try the free checks first. Compare these optional products for the specific uses below; buying equipment does not guarantee a fix.

Start with the coverage comparison and Wi-Fi Calling in step 7. A home booster is a conditional option for an indoor reception problem, not a general cure for failed calls. Check installation feasibility and carrier consent before buying; a higher-priced kit is unnecessary if the free checks solve the issue.
Shopping transparency: Links labeled “paid link” may earn us a commission if you buy. As an Amazon Associate I earn from qualifying purchases.
  • For confirmed weak indoor cellular coverage in the USOptional

    weBoost Home MultiRoom cellular signal booster — 470144

    Amplify an existing outdoor cellular signal inside part of a home. Consider it only when ordinary calls work outside but fail indoors and supported Wi-Fi Calling does not meet your needs.

    • Requires usable outdoor cellular signal; it cannot create coverage where none exists.
    • Includes indoor and outdoor antenna equipment; installation and cable routing are required.
    • Coverage depends on the outside signal and building. No guaranteed room count or calling performance.

    Consider only when: You have confirmed usable cellular service outdoors but weak coverage indoors, Wi-Fi Calling is insufficient or unavailable, and your carrier approves this US booster installation.

    Check compatibility: US kit for supported cellular bands. Check your carrier and location before buying. Register the booster with your carrier and obtain its consent before use. Follow the supplied antenna and installation requirements; use a qualified installer when placement is unsafe. It cannot fix No SIM, an inactive line, billing restrictions or a carrier outage.

    Get on Amazon Paid link · Amazon.com

Frequently asked questions

Why does the internet work but calls fail?

Wi-Fi internet access and cellular voice service are different connections. The carrier’s line and calling settings still need to work.

Should I factory-reset my iPhone?

Not as an initial test. First identify whether service, one contact, incoming calls or all calls are affected.

Will a cable, charger or signal booster fix it?

A cable or charger does not repair cellular calling. A booster can help only with a confirmed indoor coverage problem when usable signal exists outside; it cannot repair a SIM, account restriction or outage. Try supported Wi-Fi Calling first.

Why do calls go straight to voicemail when my iPhone has service?

That symptom can involve incoming-call handling, a particular caller or the carrier’s routing. Compare whether outgoing calls work and whether all callers are affected before changing Focus or call settings. It is different from SOS or No Service.

Sources and editorial transparency

Documentation checked: 2026-10-28. Our instructions are written for this guide. Interface labels can change; this is a source review, not hands-on testing of every device.

Reference titles and source dates
  • Apple — Call failures and incoming calls
  • Apple — SOS, No Service and Searching
  • Apple — Make a call with Wi-Fi Calling
  • weBoost — Home MultiRoom specifications and installation scope
  • weBoost — Carrier registration requirements

Prepared by TechTweety Editorial · Source-backed troubleshooting guide.