More than 20 Perth restaurants have been left out of pocket by a man who likes to eat and run — and a quirk of the legal system means police cannot get involved.

Chloe Debono, head of operations at The Local Shack, told ABC Radio Perth Mornings the man visited on June 5 and consumed numerous drinks, two main meals and dessert to the value of $150.

He then told staff he did not have his wallet.

"We received a call from our manager in the Perth CBD who informed us that this guy did not have his wallet on him," Ms Debono said.

"He was claiming he would come back the following day to pay and she [the waitress] could take a photo of him on her phone.

"However he didn't come back the following day."

After the incident the restaurant posted the photograph and a warning on its Facebook page.

The page was flooded with comments and it was soon discovered the man was known by up to 25 restaurants in Perth for eating and running.

Ms Debono contacted police but was told that by offering to return and pay, the man was not committing a crime.

"It's not theft because we have taken his details as surety and we have arranged for him to come the following day to pay for his meal and he has not turned up," she said.

"It falls under contractual law; it is no longer criminal because it's a contractual agreement where we have taken an assurance."

Ms Debono said she had since discovered the man did in fact give his real name.

He also provided personal documents to other restaurants as surety, including his driver's licence bearing his home address and his release papers from Hakea prison.

"He knows exactly what he is doing," Ms Debono said.

"It is basically the perfect scam."

While some other businesses are determined to fight to recover their money, Ms Debono does not think it is worth it.

"These restaurants are now willing to go all out and take this man to court, but I honestly don't believe he has anything to take," she said.

"It will be more costs for us."

She has advised her staff and other business owners not to enter into contracts with other customers who can't pay.

"We urge every restaurant, in future, to just call the police," she said.