With Black Friday sales already being advertised - Kiwis are being warned to stick to a budget

Last year, Westpac saw a 33% increase in average spend per customer on Black Friday, compared to an average Friday.

Westpac Financial Wellbeing Manager Warren Ngan Woo is advising people not to get sucked in by over-spending.

He says avoid the urge to splurge by slowing down and sticking to the items you wanted before the sales started.