Retailers are hoping to build up a Boxing Day buffer ahead of a quieter start to the new year

PriceSpy research shows Boxing Day sales are still the country's most favoured sale event, with consumer purchase interest still peaking on this day last year.

But Retail NZ Chief Executive Carolyn Young says the big challenge this year is consumers' feeling more cautious with their spending power.

She expects consumers will be watching how much they're covering their current situation before unleashing their spending.