Signal Code Not Coming? SMS and Call Code Fixes

If your Signal code is not coming, start with Signal's own troubleshooting list. It names these causes: a misformatted number, a filter that hides unknown senders, a carrier block on short codes or unknown callers, a VPN, and too many registration attempts. Signal only needs a number that can receive an SMS or a call, so most fixes are phone or carrier settings you can change in minutes.

What does Signal need to send you a code?

Signal's Register a phone number page says it plainly: "Signal uses your existing phone number" and "The number must be able to receive an insecure SMS or phone call."

You get two delivery routes. The first is an SMS. The second is a voice call: "Alternatively, you can request a verification call if you can not receive SMS. After the timer finishes counting down, tap Call me." If either route reaches you, registration works.

One case looks like a missing code but is not. The SMS can arrive while Signal fails to read it, and "If the verification code is not automatically detected, it can be entered manually." Check your messages before you request another code.

Why is your Signal code not coming?

Signal's Registration troubleshooting page (as of October 2026) lists the causes below. They are ordered so the quickest checks come first.

Basic checks: signal, number and format

• Confirm you are in range of your mobile network. Then have someone text and call the number to prove both routes work.
• Check the number on the registration screen digit by digit.
• Signal's rule: "Enter the full international phone number and omit any leading zeroes." A UK number written locally as 07... becomes +44 7..., with the 0 dropped.

Unknown-sender filters on your phone

Signal's message comes from a sender that is not in your contacts, so phone filters can hide it.

• iPhone: look in the Messages app's Unknown Senders inbox, or turn off Settings > Messages > Filter Unknown Senders.
• iPhone, call code: turn off Settings > Apps > Phone > Silence Unknown Callers, or the Call me ring never reaches you.
• Any phone: confirm you have not blocked messages from unknown senders.

Carrier blocks and opt-outs

Carriers can stop the code before it reaches your phone. Ask your provider to confirm two things: that you have not replied "STOP" to unknown senders, and that you have not opted out of business or transactional notifications.

On T-Mobile, Metro PCS, Google Fi (using T-Mobile) or any other T-Mobile based service, Signal gives two codes:

• SMS code missing: "Call #611# and ask the representative to remove the "Shortcode Blacklist" for your account."
• Call code missing: "Call #632# to turn off Scam Block."

Google Fi users can also switch the underlying carrier with dialer codes. Dial ##fiinfo## to see which network you are on now.

A VPN on Android

Signal's instruction for Android: "Disable your VPN app or check that it allows *.signal.org and TCP port 443." Many VPN apps have a split-tunnel or allow-list setting. Exempting Signal there fixes the request without turning the VPN off everywhere.

Too many attempts

Signal shows "Too many attempts?" on Android and "Registered too many times?" on iOS. The answer is the same on both: "Wait some time (1 hour, 1 day, etc.) before trying to register again." Fix every other item on this list first, then wait out the period, so the next attempt is the one that works.

Which fix matches your symptom?

Signal's page groups its advice by platform. You start from a symptom, so here is the same advice sorted that way.

On Android, if the request hangs or errors before any code is sent, look at the VPN first. If you see an attempts message, the wait is the only fix.

What if your carrier keeps blocking the code?

Sometimes you work through every step and your carrier still drops the message. Other times you would rather not tie Signal to your personal number at all. In both cases, a different number you control can receive the code for your own account.

VoidMob: mobile proxies on real 4G/5G devices, non-VoIP SMS verification and eSIM. Its numbers are non-VoIP carrier numbers. A one-time verification uses a US number that stays active for 15 minutes:

• The window can receive several codes.
• If no SMS arrives in the window, the rental cancels and refunds in full. The one exception is a service marked non-refundable at purchase.
• Once a code has been delivered, the rental cannot be refunded.
• Poll for the code instead of cancelling early. Frequent cancellations pause SMS purchasing for 24 hours.

The live price for a Signal number is below. You can also see it on the Signal SMS verification page.

Other apps fail in their own ways. For those, not receiving verification codes covers the cross-platform causes.

How do you keep a Signal account registered on a second number?

Signal stays tied to the number you registered with. A new phone or a reinstall means receiving a code on that same number again. A 15-minute number therefore suits a quick registration. It does not suit an account you plan to keep.

Two steps protect an account you keep.

Set a PIN with Registration Lock. Signal's PIN article says "A PIN can also serve as a registration lock" and "Enabling a registration lock triggers a 7-day inactivity timer if your number is registered on another device."

Keep the number reachable. The same article adds: "Registration Lock expires after 7 days of inactivity." The lock protects an active account. It does not replace holding the number.

Pick the number type by how long you need it:

• Multi-day rental: keeps the same US number for 3, 7, 14 or 30 days, with optional auto-renewal. A rental is bought for one service and receives that service's SMS for the term.
• Dedicated monthly line: one non-VoIP carrier number reserved to you, billed month to month. It accepts SMS from any service and is offered per country; see dedicated phone numbers by country. To stop, turn auto-renew off and let the period lapse.

For the longer case on owning a number versus buying codes, read dedicated non-VoIP number vs OTP. The same trade-off for a messaging account you keep is worked through in WhatsApp Business verification with non-VoIP numbers.