How to disable VOIP for Yahoo 2-step verification

Your carrier is apparently using VoIP, or they have a configuration issue, or some phone number database somewhere is just wrong. Or maybe there is some other reason for a service access block, such as an embargo or trade sanction.

Options: add a second line not using VoIP, switch to a carrier not using (or not overtly using) VoIP, or add a second factor such as an app or token or passkey.

Or you can try to fix whatever Meta or Yahoo or your (unspecified) carrier are in conflict about here.

I have used VoIP numbers from major US regional incumbent wireline telephone carriers; they’re “standard” landline phone lines and far from rare. Copper phone lines and POTS connections are going away just as fast as the carriers can migrate off them.

Note: This has nothing to do with carrier lock, or an unlocked phone. Nothing.

Wifi calling may be recognised by Yahoo as VOIP, make sure that is turned off.

Settings, Apps, Phone, Wifi calling

LD150 wrote:

Yahoo! and Facebook both offer Authenticator app authentication as an alternative, assuming they can get logged in to change the method!

Yeah, and iOS has a built-in authenticator in Passwords app in iOS 18 and later. (Available earlier too, though better hidden.)

Alternatively if Yahoo is too dumb to recognise your phone, you can change from text verification to authenticator app

https://help.yahoo.com/kb/add-two-step-verification-extra-security-sln5013.html

VoIP numbers are commonly rejected for verification and authentication by many apps, Apple ID included. They can’t be used as trusted phone numbers because they’re easy to obtain online and don’t always pass the stricter identity checks required for account security. Convenience is great—until security shows up to the party.

LD150 wrote:

The OP wants to disable VOIP, not use it.

If Facebook and Yahoo thinks the OP has VOIP then I suggest those apps are mistaken, but the nearest thing to VOIP is wifi calling. Maybe wifi calling has activated.

As Lawrence said iphone does not support VOIP, but Yahoo seems to think it does.

Here is the only possibility I can think of:

You can port a landline or VOIP phone number to any mobile phone. If this has happened that number will appear to be a VOIP number until the ITPM (International Terminating Point Master) database is updated, which does not happen in real time.

Yahoo! and Facebook both offer Authenticator app authentication as an alternative, assuming they can get logged in to change the method!

VOIP numbers used to be called “landline” numbers. The technology is different, but the purpose is the same. And yes, you can’t use them for 2 factor authentication with some apps; that is, apps that can't call the number and speak the code. So this is a limitation of Yahoo and Facebook, apparently. But this has nothing to do with your iPhone.

The OP wants to disable VOIP, not use it.

If Facebook and Yahoo thinks the OP has VOIP then I suggest those apps are mistaken, but the nearest thing to VOIP is wifi calling. Maybe wifi calling has activated.

As Lawrence said iphone does not support VOIP, but Yahoo seems to think it does.

Fantazim73 wrote:

iPhone 17 purchased unlocked phone different carrier from iPhone 15 locked different carrier iPhone17 phone unlocked carrier was the one to have me come here.

There’s a lot going on in this thread, and I’m not sure how it’s all connected.

Whether an iPhone is carrier locked, is locked to the first carrier used, or is unlocked, depends on details including the country of purchase, and whether purchased from Apple or an Apple reseller.

If you purchased in the US from anywhere other than Apple, it is very likely you purchased a so-called flex lock device (also called iPhone Flex Policy, and Reseller Flex Policy), and it locked to the first carrier used.

If you want a VoIP service, that’s not iPhone, but other phone providers can offer that, and there are add-on apps which support VoIP. Most any recent iPhone also supports Voice over LTE Calling (VoLTE).

VoIP and VoLTE are unrelated to flex lock and carrier lock.

If you have questions about a particular VoIP service, contact the service provider.

If you have questions about Yahoo services, contact Yahoo Support.

If you want to continue here, you’re going to have to explain a little more about VoIP and Yahoo, and about where this iPhone was purchased and whether it now shows as carrier-locked, and, well, what all has happened here.

The iPhone does not support VOIP, so I’m not sure what your problem is. Can you provide more information?