Answer
Policies differ by operator—some refund unused credits at the counter with a receipt, others treat balances as final. Ask before loading a large bundle on night one. Keep cards in zip bags; salt air and wet pockets kill magnetic strips faster than you expect.
Sources: Visit Ocean City
Editorial visitor guidance for Ocean City, Maryland. Confirm current Town of Ocean City, Maryland DNR, NPS Assateague, and NWS rules when regulations or safety apply.
