Portland city officials have levied their second fine against a short-term rental company for not following the rules—and the penalty is a doozy.

The city's Revenue Bureau fined the Austin, Texas, online marketplace HomeAway on May 19, charging it $326,500 for failing to register to pay transient lodging taxes, get its hosts to obtain city permits and undergo safety inspections.

The city's notice says inspectors found 330 rentals where HomeAway didn't collect taxes, and 332 rentals operating without a permit or inspection. The city fined the company $500 for each violation.

UPDATE, 4:10 pm: HomeAway co-founder Carl Shepherd confirmed late this afternoon the company had received the city's letter. He declined further comment.

In April, the city fined Vacation Home Rentals of Newburyport, Mass., $3,000 for the same violation. 

Mayor Charlie Hales led the charge last summer to legalize Airbnb and other short-term rental sites. But the city soon found few hosts were getting the required city permits and safety inspections.

The rate of noncompliance is still at 91 percent, according to recently updated data from insideairbnb.com/portland. The site, developed by technologist Murray Cox, displays where Airbnb rentals are located in the city, what type they are (complete homes, single rooms, etc.), and an estimated number of nights per year listings are booked.