No, you generally cannot use Southwest Flight Credits (LUV Vouchers or Travel Funds) to pay for the EarlyBird Check-In® fee. Southwest's payment systems typically restrict the use of flight credits to the "Base Fare" and government-imposed taxes and fees of a new flight booking. Ancillary services, such as EarlyBird Check-In, Upgraded Boarding, pet fees, or inflight Wi-Fi, must be paid for using a credit card, debit card, or PayPal at the time of purchase. However, if you have a Southwest Rapid Rewards® Priority or Performance Business Credit Card, you may receive "credits" for these purchases that appear as statement credits on your bank account. It is also important to remember that EarlyBird Check-In is non-refundable; if you cancel your flight, the money paid for the check-in service is forfeited and cannot be converted into a flight credit for future use. For the most efficient experience, it is best to bundle these costs during the initial booking phase if you are not using a card that covers the benefit.