Most car rental companies in Trier require a credit card for renting a car. This is because the credit card is used as a form of security deposit in case of any damages or unpaid fees. However, some companies may accept debit cards or cash deposits as alternatives, but it is best to check with the rental company beforehand.

To rent a car in Trier, you will typically need the following documents:

• A valid driver's license held for at least one year.
• A valid passport or ID card.
• A valid credit card in the name of the main driver for the security deposit.
• Some rental companies may also require additional proof of address or international driver's permit, so it is best to check with the specific company beforehand.

The fuel policy for car rentals in Trier can vary depending on the rental company. The most common policies are:

• Full-to-full: You receive the car with a full tank of fuel and you must return it with a full tank.
• Pre-purchase: You pay for a full tank of fuel upfront and can return the car with any fuel level.
• Refuel upon return: You can return the car with any fuel level, but you will be charged for the fuel needed to refuel the tank to the initial level.

It is important to check the fuel policy specific to your rental reservation and make sure to return the car in accordance with the policy to avoid any additional charges.

The cancellation policy for car rentals in Trier can vary depending on the rental company and the type of reservation. It is important to carefully read the terms and conditions of the rental agreement before making a reservation. Some common cancellation policies include:

• Free cancellation: You can cancel your reservation without any penalty up to a certain number of hours or days before the pick-up time.
• Partial refund: You may be eligible for a partial refund if you cancel your reservation within a specific timeframe before the pick-up time.
• No refund: If you cancel your reservation too close to the pick-up time or fail to pick up the car, you may not be entitled to a refund.

It is always recommended to check the specific cancellation policy for your reservation and consider purchasing travel insurance to protect against unexpected changes or cancellations.

Cross-border travel with a rental car from Trier is usually allowed, but it depends on the rental company and the specific country you plan to visit. Some rental companies may have restrictions or additional fees for cross-border travel. It is important to check with the rental company beforehand and inform them of your travel plans to ensure compliance with their policies. Additionally, certain countries may have specific requirements such as additional insurance or permits for driving a rental car across their borders.

In case of an accident or breakdown with a rental car in Trier, you should follow these steps:

• Ensure your safety and the safety of others by moving the vehicle to a safe location if possible.
• Contact the rental company's emergency contact number immediately to report the incident and seek guidance.
• Collect all relevant information such as the names and contact details of involved parties, witness statements, and photos of the scene.
• Follow the instructions provided by the rental company regarding the next steps, such as arranging for a replacement vehicle or submitting a claim.
• Depending on the severity of the incident, you may need to involve the local authorities by calling the police and obtaining an official accident report.

It is important to familiarize yourself with the rental company's specific procedures and insurance coverage related to accidents and breakdowns before starting your rental period.