[namecheapTA]

Burner phone numbers in the US seem to be of a particular range of numbers and can also be flagged. I used to use pay as you go burners for random tasks in the past and noticed they gave me trouble when trying to use them to get verification codes sometimes.

[remram]

I'm not sure what you mean when you say "burner phone". I know for a fact that you can get a regular prepaid plan from T-Mobile and pay for it cash, no IDs; that fits the "burner phone" requirements for me. Do you mean that every prepaid plan uses that range of numbers?

[Scoundreller]

Prepaid plan vs post-paid, probably not, but some discount prepaid providers are probably considered “less trust-worthy”, or less profitable when evaluating VoIP numbers.