Some shops and restaurants saw business increase by as much as 100 percent on Sunday, retail and catering sector representatives said, as the government released the first part of its HK$5,000 spending vouchers.
People were seen flocking to convenience stores and Octopus machines at MTR stations to collect their first HK$2,000.
On an RTHK radio show on Monday, the chairwoman of the Retail Management Association, Annie Tse, said a wide range of shops, such as furniture, electrical appliance and clothing stores, had all benefited from a surge in spending.
"More people are visiting shops and sales have been boosted. Some shops are seeing business increase by at least 50 percent. Some even saw sales double," she said.
Tse estimated that the retail sector could see a growth in business in the low double-digits in the coming months thanks to the vouchers.
She said she noticed that some shops had introduced an extra two percent service charge for digital payments, but said most had actually offered discounts to attract customers.
Speaking on the same show, Simon Wong from the Institution of Dining Art said restaurants had already seen business rise by 10 percent.
He said he expected around HK$10 billion to HK$15 billion of the government's HK$36 billion voucher scheme to be spent on his sector.
Wong added that some restaurants might have put prices up, but he attributed this to a rise in global food costs in recent months.
Meanwhile, an official at the financial secretary's office said the government does not encourage shops to increase prices or introduce extra service fees due to the spending vouchers.
Jessie Wong from the budget and tax policy unit said shops risk having their e-payment service contracts terminated by service providers if they introduce extra fees.
Consumers are very smart and will compare prices before making purchases, she said.
She also warned people against cashing out the vouchers, saying shops who let people do this may be blacklisted and law enforcement could act if any illegal activities are involved.