Warrnambool City Council's visitor economy manager David McMahon says providers are reporting their hotel, motel and caravan parks are almost full.

"It's Warrnambool's single biggest event in terms of economic impact and city branding," he said.

"The eyes of the country are on Warrnambool. The event is becoming more than just horse racing, it's a celebration of everything Warrnambool has to offer.

"People are coming earlier and leaving later to see the city's attractions. The region is starting to feel the effects of the 'I am Warrnambool' campaign which is designed to inform visitors not just that we have one of the country's best race carnivals, but one of the best regions to visit.

"The campaign is designed to promote the region in collaboration with the Great Ocean Road. I always encourage people to invite their family and friends to the city."

The city council is also running a database for accommodation at the visitor information centre and anyone looking for a bed is encouraged to call the centre. It has been contacting south-west accommodation providers and updating the vacancies available on the database for the races week.

Mr McMahon said with the city's population set to swell during the three-day carnival, accommodation was understandably in high demand.

"The carnival will inject more than $13 million into Warrnambool's economy and with so many visitors coming to town, finding accommodation for everyone is always a challenge," he said.

"It's no surprise that most operators are booked out already.

"We are encouraging providers to contact us when cancellations happen and spaces become available so that we can continually update the database and match visitors with beds. Because accommodation is at such a premium the visitor information centre continues to help people find the best suitable accommodation for their needs and it helps the industry with their vacancies. It's proving very effective."

Mr McMahon said Warrnambool was "all but full" for Easter school holidays.

"With Easter so close to ANZAC Day holidays, people only needed to take three days of annual leave to get 10 days off," he said.

"It's a perfect lead in to the May carnival. Most operators are telling us they are full and only have a couple of rooms left for these holidays and are all but full for May races. We encourage people to visit or call the info centre if they do have any accommodation available. We can help promote it."