Surcharges for Cheque payments
If there is nothing in your Written Agreement that states that if you pay by cheque you will attract a surcharge then you should not pay any surcharge. If the owner tries to impose a surcharge where there was not one previously this would be classed as a unilateral change to the Agreement and therefore must be agreed by both parties of that Agreement.
However, if your Written Agreement does state that there will be a surcharge for paying by cheque then the Consumer Rights (Payment Surcharges) Regulations state: “A trader must not charge consumers, in respect of the use of a given means of payment, fees that exceed the cost borne by the trader for the use of that means.” Therefore they can only charge the same as they are charged by the bank (usually around £0.60).
Unfair Contract Regulations also require active consent of the consumer (resident) before surcharges can be added.