The competition and consumer protection service of the commerce ministry has warned shoppers that although set times for sales have been scrapped, shops are still obliged to list both the original price and the discount rates for most goods when they hold a sale.
The regulations apply for clothes and other textiles, fashion accessories, footwear, home equipment and furniture of any kind.
Offenders face a fine up to € 1,500 and/or imprisonment up to six months.
The consumer service in an announcement on Wednesday said that it would step up its checks to ensure the law is being followed and urged consumers to report breaches to its office.
The law on sales was amended by a unanimous vote by parliament on March 10.