Money expert Martin Lewis says mobile phone customers can save money by sending a text to a 5-digit number.

Company-sponsored text numbers are different. There’s no area code, no digit spacing. Will the scammers figure out how to make it look like a 4-digit number?

Legit businesses that text you don’t use phone numbers like a 10-digit phone number and do not use emails. But what if the text you get looks so real and you're anxious about your account?