Knowing what the new law entails is important, said retail experts.
Professor Bernd Schmitt, executive director of the Institute on Asian Consumer Insights, said the onus is on retailers to find out about the law.
Prof Schmitt said even though ignorant retailers might not turn regular customers away, consumers will appreciate retailers who honour this policy.
Mr Samuel Tan, 51, course manager for the diploma in retail management at Temasek Polytechnic, agreed.
He said: "Retailers cannot deny the fact that this law has been introduced. It is up to the retailers to find out about the 'lemon law'.
"They cannot always use 'I don't know' as an excuse. Shoppers may not want to go back to the stores if retailers are not responding positively to the law."
What about the stores that have their own policies on returns and exchanges?
Lawyer Foo Cheow Ming said the lemon law overrides individual store policies.
The partner at law firm KhattarWong added: "The new law takes precedence over everything else.
"Store policies kick in only if the terms they offer are superior to the consumer rights covered under the new law."
He suggested that stores review their standard operating procedures and invoices.
- Additional reporting by Foo Jie Ying and Koh Hui Theng
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