[ganlaw]

Twitter lets you register without a phone number. All you need is a email

[judge2020]

I believe recently it will lock your account for "suspicious activity" or something until you verify by adding a phone number.

[flingo]

They've done that for a couple of years.

If you can actually submit a support ticket, get them to agree that a phone number is not required (like it says on their website), and to reply when that's done, you'll get your account unlocked after a few days. (usually)

[typenil]

That's been my experience.