A Blackpool hotel is being investigated by Trading Standards over claims it fined a couple £100 for placing a bad review on the TripAdvisor website.
Tony and Jan Jenkinson said they were hit with the added credit card charge after writing the Broadway Hotel was a "rotten stinking hovel" on the review site following a disappointing overnight stay.
Mrs Jenkinson said the couple were told by the hotel they had contravened the "no bad review policy" in the terms and conditions included on the booking form for their £36-a-night room.
The policy reads: "Despite the fact that repeat customers and couples love our hotel, your friends and family may not. For every bad review left on any website, the group organiser will be charged a maximum £100 per review."
Blackpool Trading Standards are investigating whether the policy breached regulations on unfair terms in consumer contracts, while the Jenkinsons are seeking a refund through their credit card company.
Mrs Jenkinson, from Whitehaven, told BBC News the hotel was "dirty and falling apart" and said staff told them they were already aware that the room's hot water tap and kettle did not work, while a chest of drawers was "falling apart".
ITV News has been so far unable to contact the hotel manager for a response to the claims.
Councillor John McCreesh, a cabinet member for trading standards, condemned any attempts by hotels to silence guests.
The Broadway Hotel is advertised as offering "budget en suite rooms above a lively bar on the Blackpool seafront with a games room and restaurant".
A majority 147 of the 256 reviews on TripAdvisor rate the hotel on Burlington Road West as "terrible", though 35 people commended it as "very good" and 17 people rated it "excellent".
Update: According to Blackpool Council, the Broadway Hotel has subsequently withdrawn the couple's fine and removed its "no bad review policy" for its terms and conditions.