What Google Checks When You Add a Number
Google does not publish a list of accepted or refused number types. What it does state is that it limits some carriers that are often used for abuse when unlocking certain services. Four things shape the verification step:
Line type. This is the signal the table below breaks down: whether the carrier records the number as a mobile line or as an online/VoIP one.
Region. Verification options vary by account, device, and region.
Delivery method. Verification arrives by SMS text or voice call. If a text is delayed, Google’s own guidance says to wait a few minutes or switch to the voice-call option — which also works on a home phone.
Reuse limits. Google caps the number of accounts a single number can create and how many times it can be used for verification. Once that limit is reached, Google’s suggested fix is to use a different number — from a family member, friend, or a different carrier.
None of these are published as numeric thresholds or fixed country lists.
Which Numbers Work with Google Verification
The table below covers the line types most people try, from personal SIMs to shared public inboxes.
| Number type | Accepted | Notes |
|---|---|---|
| Non-VoIP mobile (US or AU) | Yes | Accepted by every service; the standard other types are measured against |
| VoIP / online number | Often refused | Per the FCC, VoIP turns your voice into a digital signal sent over the internet |
| Landline (voice call only) | Sometimes | Can receive the voice-call option but cannot receive SMS; not suitable as a recovery phone |
| Public receive-SMS / shared inbox | Often refused | Many people use the same number, and Google limits how many times a number can be used for verification |
| Number from another country | Depends | Verification options vary by account, device, and region; a foreign number clears the check when carriers list it as mobile (non-VoIP) |
The word “virtual” on its own says little; the carrier’s classification of the line is what places a number in one row of this table or another.
Common mistake: Trying a public receive-SMS number found through a free online inbox. These numbers are shared with anyone who visits the page, and numbers like that are often turned down.
Creating a Google Account with a Second Number
Open the Google account creation page and choose your account type: personal, child, or business. The sign-up flow asks for a Gmail address (or an existing email address, or a phone number), birthday, gender, username, and password. Adding a phone is marked Optional at this stage.
Complete the required fields and advance. Work through the form until Google either skips the phone step or presents a verification screen. Google sometimes requires phone verification before you create an account, so the screen may or may not appear.
Prepare your separate number before entering it. Use a mobile (non-VoIP) line that you can keep using. If you are unsure how a number is classified, the carrier or the service you obtained it from should be able to confirm the line type.
Enter the number and choose text or call. If the SMS is delayed, wait a few minutes before requesting another code. If it still does not arrive, switch to the voice-call option — Google lists text and call as the two options, and the call works on a home phone.
Enter the code to complete verification. Once entered correctly, this step is done.
Decide whether to save the number as a recovery phone. A recovery phone should be a mobile that receives texts, belongs only to you, and that you use regularly. Do not use a Google Voice number as your recovery phone; Google explicitly warns this can lock you out of the account.
Pro tip: If a text does not arrive, try the voice-call option before concluding the number is blocked.
Errors You May See
“This phone number cannot be used for verification”
This phone number cannot be used for verification
Google doesn’t explain each refusal. It says it limits some carriers that are often used for abuse, and that options vary by account, device, and region.
What to do: try a different number, ideally a mobile (non-VoIP) line on a different carrier.
“This phone number has been used too many times for verification”
This phone number has been used too many times for verification
This message means the number has hit Google’s reuse limit. The number itself may be valid, but it is exhausted for this purpose.
What to do: Google’s guidance is to use a different number — from a family member, friend, or a different carrier. There is no published process to reset a number’s verification count; the used too many times error has its own page.
Keeping the Account After Sign-Up
One-time activation vs. saved recovery number
If the number was only used to pass a single verification screen, keep it out of your recovery settings. Before you stop using it, set up backup codes or an authenticator app from Google’s 2-Step Verification options.
If the number is saved as a recovery phone and you are renting it, the situation is different. When the rental expires, you lose the ability to receive recovery codes sent to that number. Google notes that recovery phone changes may take up to 7 days to take effect, so there is a window of risk even after you update the field. Apple handles this differently: an account with two-factor authentication must keep a trusted number; see virtual numbers for Apple ID.
The Google Voice warning
Google explicitly states not to use a Google Voice number as your recovery phone, because you could lock yourself out of your account.
Stronger alternatives to SMS codes
Relying on any phone number for account security carries trade-offs. NIST SP 800-63B-4 classes SMS and voice (PSTN) authentication as “restricted” and requires that verifiers offer alternatives. Google’s 2-Step Verification guidance warns that text and call codes can be vulnerable to phone number-based hacks. It recommends Google prompts and also offers passkeys, security keys, authenticator apps, and backup codes.
Decision framework:
- Number needed only once to pass sign-up → one-time activation is sufficient; do not save it as recovery.
- Ongoing account recovery needed → use a non-VoIP mobile you control long-term, and add a backup method (authenticator app or backup codes).
- Considering a Google Voice number as recovery → do not; use an authenticator app or security key instead.
Backup codes, one of Google’s 2-Step Verification options, do not depend on any phone line, so they still work if the phone number later becomes unreachable.
Frequently Asked Questions
Will Google reject a virtual phone number during verification?
It depends on the line type. A virtual number that carriers file as mobile rather than VoIP gets through; online and VoIP numbers are often rejected. Google says only that it limits some carriers that are often used for abuse.
Is there a limit on how often one number can be used?
Yes. Google limits the number of accounts each number can create and how many times a number can be used for verification. Once that limit is reached, Google shows the used-too-many-times message, whether the number is virtual or not.
Can I use a Google Voice number as my recovery phone?
Google explicitly advises against this, because you could lock yourself out of your account. Use a mobile number you control or a non-SMS method instead.
Do I have to add a phone number when creating a Google account?
Not always. Google marks adding a phone as Optional in the standard sign-up flow, but it sometimes requires phone verification to confirm you are a real person. Creating a Gmail account without a phone number is covered separately.
What should I do if my number is accepted for sign-up but later stops receiving Google codes?
Check whether the number is still active and able to receive SMS from other senders. If it has expired or been reassigned, update your recovery phone in Google account settings — and note that changes may take up to 7 days to take effect. Use backup codes or an authenticator app to maintain access in the meantime. If you have no backup method and cannot receive codes, Google’s account recovery process is the remaining option, though success is not assured.