When you sign up for a free trial, you are enrolling in an Equifax subscription product. If you don't cancel the product during the trial period, the payment method you provided during registration will be charged for each month you continue your subscription until you cancel.
Please note that prior to fulfilling your order under any free trial, a prior authorization may be requested on your credit or debit card to ensure it is valid. You may see a "pending" charge on your credit or debit card statement. The authorization is removed by your financial institution automatically; how long that takes depends on your financial institution.