Can a vendor unilaterally add a 3% cc fee if it was not contained in the original contract. Emailed change eff 1 Jan.

Question

I signed a contract in state of MD): 
 
If Organization wishes to pay any portion of its obligation by credit card, they may do so and request additional payments using the iVvy link provided to them when they received this contract up until 30 days prior to the event date. Once it is within 30 days prior to event date, payment may be made by cash, check or money order. TVR accepts the following credit cards: American Express, Visa, Discover, MasterCard, and Diners Card. 
 
A final master account bill, containing receipts and other back-up information, will be e-mailed to the group within ten (10) business days of the Organization’s departure. Master account charges may be paid in the form of cash, credit card, check or bank transfer. There is a $35.00 charge for all returned checks. All master account charges not paid within 20 days of the billing date will bear interest at the lower of the rate of 2% per month, compounded monthly,

Scott Scherr · Answer

An attorney would need to review the entire contract to render an opinion. However, a business can change the terms of its contract periodically. For example, Comcast changes the terms of its contract with its customers regularly. The rates and service charges increase and the fine print changes. The customer does not have to continue with Comcast. 
 
If the contract is for a set period of time, then one party cannot unilaterally change the terms. If the Orioles sign you to a guaranteed three year contract, they cannot terminate the contract after one year and refuse to pay you or change your annual salary.

Q: Can a vendor unilaterally add a 3% cc fee if it was not contained in the original contract. Emailed change eff 1 Jan.