The browsers you have marked as "trusted browsers" on a computer won't ask for a verification code when you sign in to your ChARM account for the next 180 days. Select the Trust this browser option when entering your verification code during sign-in.
To view/delete trusted browsers in your account, follow the steps given below:
This will list the details of the browsers you've trusted on any computer IP address. You may delete a trusted browser at any time from the above list using the Remove link. Once you revoke the trusted status of a browser in a computer, you will be required to enter a verification code the next time you sign-in using the respective browser in the particular computer.