R.I. Gen. Laws § 28-14.1-4: Credit cards.

Where tips are charged on a credit card and the employer must pay the credit card company a percentage on each sale, the employer may deduct that percentage from the employee’s tips, provided that the employer notifies the employee of the deduction. This charge on the tip may not reduce the employee’s wage below the required minimum wage. The amount due the employee must be paid no later than the regular pay day and may not be held while the employer is awaiting reimbursement from the credit card company.