SignalSolved

No signal? Let’s find out why.

Last updated August 29, 2026.

Short answer

Sudden phone signal loss almost always comes down to one of five things: a network outage, a stuck network registration (fixed by airplane mode or a restart), a SIM/eSIM problem, an account block (billing, suspension, or a number transfer), or a coverage gap — often just indoors. Answer the questions below and you’ll get the most likely cause and the exact next step. Nothing to buy, nothing to install.

Question 1

What does your phone’s status bar show right now?

Look at the top of the screen, where the signal bars normally are.

If you only do five things, do these — in order

  1. Rule out the network before you touch anything. Check whether people around you on the same carrier have service, or open your carrier’s status page over Wi-Fi. If it’s an outage, nothing on your phone will fix it.
  2. Airplane mode for 30 seconds, then restart. Airplane mode forces the phone to re-register with the network; a restart clears deeper radio state. These two fix the most common sudden No Service cases.
  3. Check the SIM or eSIM. In your cellular settings, confirm your line is listed and active. Reseat a physical SIM; toggle an eSIM line off and on — but never delete the eSIM profile yourself.
  4. Check the account over Wi-Fi. Log in to your carrier’s app or website. A missed payment, a suspended line, or a number transfer in progress silently stops service — the phone just shows No Service.
  5. Then look at software and settings. Install any pending carrier-settings update, confirm VoLTE is on, and as a last resort reset network settings (it forgets saved Wi-Fi passwords). Still down? It’s carrier time — tell them what you tried.

The whole decision path, in text

Prefer reading to clicking — or browsing without JavaScript? This is the complete tree the tool above walks through. Follow the “go to” links like a choose-your-own-adventure.

Start: What does your phone’s status bar show right now?

Look at the top of the screen, where the signal bars normally are.

Question 2: Do other people nearby on the same carrier still have service?

Ask someone around you, or check your carrier’s status page over Wi-Fi (links are in the outage result).

Question 3: Is the problem everywhere you go, or mostly in one place?

Question 4: Which of these best fits that place?

Question 5: Have you tried airplane mode and a restart yet?

Thirty seconds of airplane mode forces the phone to re-register on the network; a restart clears deeper radio state.

Question 6: In Settings, does your SIM or eSIM still show up as active?

Find the SIM list in your phone’s cellular/network settings (the exact menu varies by phone). Your line should be listed and turned on.

Question 7: Could anything be pausing your service on the account side?

A missed payment, a suspended line, a number transfer (port) in progress, or a reported-lost flag can each cut service with no warning on the phone itself.

Question 8: Did this start right after an OS update, a new-phone setup, or a settings change?

The outcomes

Your phone can reach a network for emergency calls — just not your carrier’s network.

Do this: Treat it as a coverage, outage, or account problem with your own carrier — not a broken phone. Start with 30 seconds of airplane mode, then check your carrier’s status page over Wi-Fi.

“SOS” means the phone sees some carrier’s signal that will carry a 911 call, but cannot register on yours. You can still call emergency services while it shows.

Read the full guide: SOS Only / Emergency calls only: what it actually means →

Signal isn’t your problem — the service riding on it is.

Do this: Pin down which direction fails: try a call, a text, and a web page with Wi-Fi turned off. The combination that fails tells you whether it’s voice provisioning, data settings, or the plan itself.

Read the full guide: Calls fail but data works (and the reverse) →

This is bigger than your phone — it looks like a local outage.

Do this: Confirm on your carrier’s status page (links below), then turn on Wi-Fi calling so calls and texts keep working over your home or office internet while you wait it out.

Outages usually resolve without you doing anything. If the status page shows nothing and neighbors on the same carrier are still down hours later, report it — carriers don’t see every local failure immediately.

Read the full guide: Is it an outage or just my phone? Three ways to tell →

Your new carrier is probably weaker on the radio bands that reach that spot.

Do this: Compare the new carrier’s coverage map for that exact address with what you actually get, and turn on Wi-Fi calling there. If the spot matters daily, band mismatch is a legitimate reason to use a return window.

Carriers hold different low-band spectrum in each area, and low bands are what penetrate buildings — so the same phone can go from three bars to one by switching networks.

Read the full guide: I switched carriers and my signal got worse — band mismatch explained →

That’s building physics — the walls are eating the signal.

Do this: Turn on Wi-Fi calling for that location first: it’s free and fixes calls and texts at home for most people. Then work the indoor fix ladder if you need more.

Read the full guide: Indoor cell coverage problems and fixes →

Something changed around that spot — tower work, a network change, or new construction.

Do this: Report the dead zone to your carrier (they log these and can tell you about local tower work), and turn on Wi-Fi calling so the location stops mattering in the meantime.

Read the full guide: Wi-Fi calling: when it saves you and how to turn it on →

Do the two 30-second resets first — they fix the most common causes of sudden No Service.

Do this: Airplane mode on, wait 30 seconds, off. No change? Restart the phone. Still nothing? In your network settings, turn off automatic network selection, pick your carrier manually, then turn automatic back on.

Read the full guide: My phone suddenly says No Service — what to check, in order →

Your SIM — physical or eSIM — is the prime suspect.

Do this: Physical SIM: power off, take it out, check for damage, reseat it — and test it in another phone if you can. eSIM: toggle the line off and on in settings, but do not delete the eSIM profile; if it’s gone or keeps erroring, only your carrier can reissue it.

Read the full guide: Is my SIM dead? How to tell in five minutes →

A service block looks exactly like lost signal — the phone can’t tell you why.

Do this: Log in to your carrier’s app or website over Wi-Fi and check the line’s status and billing. A suspended line, an in-progress number transfer, or a lost/stolen flag each silently stop service.

Read the full guide: Why your phone line was suspended — and which cause it is →

Software state is the likely culprit — the radio’s settings, not the radio.

Do this: Install any pending carrier-settings update, make sure VoLTE (voice over LTE) is on, and as a last resort reset network settings — note that this forgets saved Wi-Fi passwords.

Read the full guide: No service after a phone update: what actually broke →

You’ve ruled out everything fixable at home — this one needs your carrier.

Do this: Contact them with the specifics: when it started, where it happens, what the status bar says, and that you already tried airplane mode, a restart, reseating the SIM (or toggling the eSIM), and checked the account. That list skips the first twenty minutes of scripted support.

Read the full guide: My phone suddenly says No Service — what to check, in order →

Sources, dates & limitations

Limitations & caveats

  • This triage identifies the most likely cause — it cannot see your carrier’s systems, so account and provisioning outcomes must be confirmed with the carrier.
  • Device steps are phrased generically; menu names and locations vary by phone maker and OS version.
  • Carrier status links go to each carrier’s own page; we link out and never scrape or restate their outage data.

Practical next steps

  1. Phone works, but signal is weak indoors?
  2. Thinking of switching networks? Check coverage first
  3. Find out which network your prepaid brand really uses
  4. Why coverage maps promise more than reality delivers
  5. Look up a term (VoLTE, band, eSIM…)

Frequently asked questions

What does “SOS Only” actually mean?

Your phone cannot register on your carrier’s network, but it can see another network that will carry an emergency call — 911 still works while SOS shows. It is a coverage, outage, or account problem with your own carrier, not a broken phone.

Why does my phone show bars but nothing works?

Bars measure radio signal strength only. Calls and data ride services on top of that signal — if provisioning, VoLTE settings, or your plan are broken, the radio can be fine while the service fails. The triage separates those cases.

Does airplane mode really fix anything?

Yes, more often than it should: it forces the phone to drop and re-register its network connection, which clears stuck registrations after tower handoffs, flights, or dead zones. It takes 30 seconds and is always the first thing to try.

Will this tool tell me my exact problem for certain?

No — it narrows to the most likely cause and gives you the next concrete step, in the order that rules things out fastest. Some outcomes genuinely need the carrier’s side of the system; the tool tells you exactly what to say when that’s the case.

No guarantee. Coverage and availability change and can differ between neighboring addresses. Results here are informational, sourced and dated where possible, and not a guarantee of service. Always verify directly with the provider before ordering. Spotted something wrong? Report a correction.