Car insurance changes

What is the name of your state (only U.S. law)? Utah.
I am wondering if it is illegal for a car insurance company to change your rate in the middle of your policy term? They said the reason was an increase in mileage.
Ssnl.robinson

Was it during the first 60 days of the policy?

Or did you lie on the application about the type of use/annual mileage?

Lying would justify a cancellation, not really a rate increase midterm (after the freelook period which can be more or less than 60 days, depending upon the state).

OP did you have a conversation with a CSR or your agent about your mileage? If you did, you may have inadvertently given them permission to increase your mileage listed, which in turn, increased your rate.

You'll need to provide more information in order to get a more specific answer.