Modifying an existing car lease contract is generally possible, but it depends on the terms of your lease agreement and the policies of the leasing company. Common modifications include extending the lease term and/or adjusting the mileage allowance.. However, these changes typically require approval from the leasing company and may involve additional fees or revised monthly payments. At Best Deal Auto Leasing, we assist our clients in navigating these modifications by leveraging our strong relationships with leasing companies to negotiate favorable terms whenever possible. If you’re considering modifying your lease, it’s best to consult with one of our experienced brokers to explore your options and ensure the changes align with your needs and financial situation.