Chris Hough says he is losing customers by the dozen after his phone line was disconnected.
The 46-year-old, who runs the Martonian Inn at Sewerby, said he used to get “hundreds of calls a day”.
But he says BT pulled the plug on him on March 1 without any prior warning.
Mr Hough said he got a letter from BT stating another customer had asked to take over his phone number but although the letter was dated February 20, he didn’t receive it until March 2.
It said that Mr Hough should get in touch by February 29 or his line would be cut off. - but the deadline had passed by the time he received the letter.
BT wrote: “Dear Customer. We are stopping your service. Another customer has asked to take over the telephone line at your address on March 1.”
Mr Hough said: “I can’t understand how someone can just take over my number. I have been with BT for 11 years.
“We have missed Mother’s Day. Customers are not aware that we are open or not.
“There is a noticeable drop in footfall. We have had no apology whatsoever. It must happen to other people.”
The businessman has also criticised BT’s customer service, after saying a member of staff promised to call him back in early March, but never did.
BT apologised to Mr Hough and said they are investigating.
A spokesman said: “We are very sorry that this has happened and for the subsequent poor customer service Mr Hough has received.
“We will look into the complaint as quickly as possible and keep Mr Hough updated throughout.”