[Cordiali]

Tangentially related, when websites mess up the digit grouping in phone number input fields, I've noticed it becomes quite hard to read. Must be a headache to get it right though, because it's a convention that changes from country to country, but it's easily worse than not grouping the digits.

[toast0]

Not that it's always right, but Google's libphonenumber has formatting rules for phone numbers that work pretty well. But you need to know the right country, which isn't always easy; people may enter a local number and the site context isn't always enough to know what country is implied.