Why Can’t New Numbers Call My vivo Y51 Pro?

If new numbers cannot call your vivo Y51 Pro, the problem is usually caused by a call blocking setting, spam filter, Do Not Disturb mode, SIM issue, weak network signal, or a carrier-side restriction.

Start with the simple checks first. Make sure unknown numbers are not blocked, check your blacklist, turn off Do Not Disturb, restart the phone, then test calls from both saved and unsaved numbers.

Quick answer

New numbers may not be able to call your vivo Y51 Pro because the phone is blocking unknown callers, rejecting blacklisted numbers, filtering spam calls, forwarding calls, or having a SIM or network issue.

Go to Phone > three-dot menu > Settings and check the call blocking, rejection, spam, and caller ID settings. Then check Settings > Sound & vibration > Do Not Disturb, restart the phone, and test again using a number that is not saved in your contacts.

vivo Y51 Pro call problem diagnostic table

Symptom	Likely cause	Check first
Only saved contacts can call	Unknown caller blocking	Phone app call blocking settings
New numbers go straight to missed calls	Do Not Disturb or spam filter	DND and call screening settings
One number cannot call you	Number is blocked	Blacklist or blocked numbers
All new numbers fail	Carrier, SIM, or network issue	SIM signal and network mode
Calls fail only in one location	Weak signal	Mobile signal strength
Calls stop after using a call blocker app	Third-party app filtering calls	Truecaller, Hiya, or similar apps
Call rings on another phone	Call forwarding	Call forwarding settings
Unknown numbers fail after an update	Settings changed or app conflict	Restart and update apps

Why new numbers cannot call your vivo Y51 Pro

The most common reason is that your phone is treating unknown callers as unwanted calls.

This can happen if you turned on a setting that blocks unknown numbers, added a number to the blacklist by mistake, enabled Do Not Disturb, installed a spam-blocking app, or changed SIM and network settings.

vivo phones also include rejection and blacklist settings under the Phone app or system phone settings, depending on the Funtouch OS version and region. The exact wording may vary, but the checks below should point you to the right place.

1. Check if unknown numbers are blocked

Start here if saved contacts can call you, but new numbers cannot.

1. Open the Phone app.
2. Tap the three-dot menu.
3. Tap Settings.
4. Look for Blocked numbers, Call blocking, Rejection, or Blacklist.
5. Turn off any option that blocks unknown, private, hidden, or unsaved numbers.
6. Ask someone with a new number to call you again.

On some vivo phones, the path may be closer to:

Settings > System app settings > Phone > Rejection

Look for anything that blocks calls from unknown numbers or numbers not in your contacts.

This is the most likely fix if the phone still receives calls from family, friends, and saved contacts.

2. Remove numbers from the blacklist

A new caller may be blocked because their number, or a similar number pattern, was added to your blacklist.

1. Open Phone.
2. Tap the three-dot menu.
3. Go to Settings.
4. Open Blocked numbers, Blacklist, or Rejection.
5. Review the blocked list.
6. Remove any number that should be allowed to call you.

Also check whether you blocked numbers beginning with a certain prefix. Some spam filters can block groups of numbers instead of one exact contact.

After removing the number, restart the phone and ask the person to call again.

3. Turn off Do Not Disturb

Do Not Disturb can silence calls from numbers that are not saved in your contacts.

1. Open Settings.
2. Tap Sound & vibration.
3. Tap Do Not Disturb.
4. Turn it off.
5. If you want to keep it on, check Allowed calls.
6. Set calls to allow Anyone or adjust the contact rules.

This matters because some DND settings only allow favorite contacts, repeated callers, or saved contacts.

If new numbers call but your phone does not ring, this setting is worth checking.

4. Check call forwarding

Call forwarding can send incoming calls somewhere else before your vivo Y51 Pro rings.

1. Open the Phone app.
2. Tap the three-dot menu.
3. Tap Settings.
4. Look for Calling accounts, Supplementary services, or Call forwarding.
5. Turn off call forwarding options you do not use.

Check these options:

Setting	What it does
Always forward	Sends all calls to another number
Forward when busy	Sends calls away when you are on another call
Forward when unanswered	Sends calls away if you do not pick up
Forward when unreachable	Sends calls away when your phone has no signal

If you recently changed SIM cards, used another phone, or activated voicemail settings, call forwarding may have been turned on without you noticing.

5. Disable spam call filtering apps

If you use Truecaller, Hiya, a carrier spam app, or another call blocker, it may be stopping new numbers before they reach your Phone app.

1. Open the spam blocker or caller ID app.
2. Check its blocking settings.
3. Turn off automatic blocking for unknown numbers.
4. Disable aggressive spam protection.
5. Test a call from a new number.

You can also test by temporarily uninstalling the app.

If new numbers can call after removing the app, the issue is not your vivo Y51 Pro hardware. It is the filtering rule inside the app.

6. Check if the caller is using a private or hidden number

Some phones and carriers block private numbers by default.

Ask the person calling you to turn on caller ID or call from a visible number.

On their phone, they should check whether their number is hidden. If they are calling as Private number, Unknown, or No caller ID, your vivo phone or carrier may reject the call.

This is common with business lines, office extensions, internet calling services, and some VoIP apps.

7. Restart your vivo Y51 Pro

A restart can clear temporary phone app or network problems.

1. Press and hold the Power button.
2. Tap Restart.
3. Wait for the phone to turn back on.
4. Let it reconnect to the network.
5. Test the call again.

This will not delete your personal files.

Restarting is especially useful if the problem started after a software update, SIM change, app update, or poor signal day.

8. Check your SIM card and mobile signal

If your phone is not properly connected to the mobile network, incoming calls from new numbers may fail or go straight to missed calls.

1. Check the signal bars at the top of the screen.
2. Move to an open area with better signal.
3. Turn Airplane mode on for 10 seconds.
4. Turn Airplane mode off.
5. Wait for the network to reconnect.
6. Test the call again.

If the issue continues:

1. Turn off the phone.
2. Remove the SIM card.
3. Check for dirt or damage.
4. Reinsert the SIM properly.
5. Turn the phone back on.

Try the SIM in another phone if possible. If new numbers still cannot call that SIM, the issue may be with your carrier account, not the vivo Y51 Pro.

9. Reset network settings

Resetting network settings can fix broken mobile network, SIM, Bluetooth, or Wi-Fi configuration issues.

1. Open Settings.
2. Tap System management.
3. Tap Backup & Reset or Reset options.
4. Tap Reset network settings.
5. Confirm the reset.
6. Restart the phone.

This usually removes saved Wi-Fi networks, Bluetooth pairings, and mobile network preferences. It should not delete your photos, apps, or personal files.

Use this if calls from new numbers still fail after checking blocking, DND, SIM, and signal settings.

10. Contact your carrier or vivo support

If none of the fixes work, the issue may be outside your phone.

Contact your carrier and ask them to check:

Carrier-side issue	Why it matters
Incoming call restriction	Can block some or all incoming calls
Spam protection service	May reject unknown callers
SIM provisioning	SIM may not be correctly activated for calls
Call forwarding	Can be active at network level
Number barring	May block certain call types
VoLTE or network compatibility	Can affect call routing

Also contact vivo support if your phone drops calls, shows no signal often, cannot receive calls from anyone, or started failing after damage, water exposure, or a repair.

Should you factory reset your vivo Y51 Pro?

Do not factory reset the phone yet.

A factory reset should be the last option because it erases your data. Try the 10 fixes above first, especially call blocking, blacklist, Do Not Disturb, spam apps, SIM checks, and network reset.

Only consider a factory reset if vivo support or your carrier confirms that your phone settings are likely corrupted and you already backed up your data.

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