Yahoo is one of the few mail providers where a phone number is effectively mandatory: signup without SMS confirmation is not offered, and the number becomes the default recovery channel. A virtual number from Get-SMS completes Yahoo's check in under a minute — useful when you need a separate mailbox for registrations, newsletters or app testing without handing Yahoo your personal number.
Yahoo validates numbers strictly and remembers them for a long time: a number that already created a mailbox returns «this phone number cannot be used» or silently refuses to send the code. As always, cancellation is free if no SMS arrived — take the next number, and prefer switching the country pool after a rejection.
Because the registration number doubles as the recovery channel, replace it as soon as the mailbox is created: in Yahoo account security settings add a recovery email and remove or update the phone. Yahoo periodically asks for re-confirmation on logins from new locations, and if the expired one-time number is still listed as the only recovery option, a locked mailbox becomes unrecoverable. With that one habit, mailboxes registered on virtual numbers live for years. All country pools work with Yahoo; Australia and Portugal numbers have the smoothest first-attempt rate.
Worth knowing: a Yahoo ID also covers the wider Yahoo ecosystem — Finance watchlists, Fantasy Sports and AOL mail all accept the same login. One verified registration, done properly, is enough for all of them.