The Commerce Commission is proposing to give shoppers greater control over so-called add-on deals, such as insurance schemes connected with the purchase of another product.
The commission said New Zealand businesses should follow the example of Air New Zealand, which had agreed to change the way it sells travel insurance.
Instead of having to opt out, customers would have to opt in to the deal.
The commission said this would give customers greater choice to buy or not buy add-ons, or to buy one of their choice.
Its chairman, Mark Berry, said the current requirement that buyers must opt out if they wanted to avoid the deal was a problem.
"We think that these practises have potential problems. There will be consumers who inadvertently buy products that they don't realise are on the shopping list until it's too late."
The Commerce Commission said the problem was mainly, but not exclusively, with online sales.