There is no single car rental deposit in İçmeler and Marmaris. Koral Rent a Car publishes minimums from 1,500 TL for economy to 4,000 TL for premium, and its contract reserves the right to ask for more. Eskol Travel charges a flat 5,000 TL on every class. Sixt Turkey lists 4,000 TL economy, 4,500 TL middle, 5,000 TL upper and van, 6,000 TL special luxury. Europcar's Marmaris listing on Enuygun shows 4,000 TRY for a Renault Clio or Fiat Egea and 4,500 TRY for a Ford Puma. The reviewed local Marmaris sources publish their deposits in Turkish lira, but euro deposits are documented in the same province: €500 (Everyday Rent a Car, Dalaman, complaint dated 28.05.2026) and €900 (Hello Car Rental, Dalaman, review dated 09.05.2025). Turkey's rental regulation, Motorlu Kara Taşıtlarının Kiralanması Hakkında Yönetmelik, was published in the Resmî Gazete on 15 August 2026, sayı 33341. Article 14 caps the deposit at the price of three rental days for rentals of 1 to 6 days and seven rental days for rentals of 7 to 29 days, and requires deposit operations to be completed within the seven days following the end of the contract. Article 23 sets its entry into force at 1 January 2027, so those caps and that seven-day duty do not govern a 2026-season rental. Documented refund practice is wide: Enterprise Turkey cites 1 to 10 working days of bank processing, Enuygun cites 3 to 14 working days and up to 21 days for foreign cards, while customer complaints record €500 unrefunded 17 days after a return on 11.05.2026 and 24,500 TL unrefunded 46 days after a return on 22.09.2025. If a deposit is not released, send a written claim to the rental firm with the POS or pre-authorisation receipt, the itemised invoice and the contract clause behind each deduction, then apply to the Tüketici Hakem Heyeti, which handles disputes below 186,000 TL and accepts a passport number from a non-resident, and open a parallel dispute with your own card issuer.