HB 4124 regulates the charging of swipe fees on certain electronic payment transactions. The bill mandates that state and local taxes, as well as gratuities separately listed on a payment invoice, must be excluded from the total amount on which a swipe fee is charged. It requires payment card networks to either deduct these amounts at the time of settlement or provide merchants with a rebate equal to the portion of swipe fees attributable to these excluded amounts. The bill prohibits payment card issuers from adjusting fee structures to circumvent this regulation. Violators are subject to civil penalties of up to $1,000 per violation, and the Texas Attorney General is authorized to seek restitution for merchants overcharged due to noncompliance.