A third of people say they double their spending on non-essentials on payday, a survey has found.
Some 32% of people double their discretionary spending on the day they get their hands on their pay packet, according to Post Office Money and the Centre for Economics and Business Research (Cebr).
The average spend on non-essentials on payday was £55, across the UK-wide survey of more than 2,000 people.
People were also likely to front-load their spending earlier on in the month, or earmark their money for future purchases, when they had cash newly sitting in their bank account.
Three in 10 (29%) people will shop for non-essential items, and a quarter (26%) will book tickets or make plans to socialise in the first week after payday.
But the feeling of wealth is fleeting - and by the week before their next pay packet is due, many people admit to feeling stretched.
Nearly a fifth (19%) dip into their savings to cover costs, while 28% feel as though they are running out of money as they wait to be paid.
The research also found people make two unplanned purchases on average each week.
Scrolling through mobile phones, having a bad day and feeling stressed or tired were common spending triggers.
Nearly one in 10 (8%) people admit they find it difficult to browse online without spending money.
One in five (20%) people were more likely to spend after a bad day and 13% would fork out cash to make life more convenient - something which tended to happen when people felt stressed or tired, the survey found.
Ross Hunter, head of product at Post Office Money said: "Saving can be hard, as anyone who has tried to stick to a budget knows.
"However, realising what can trigger your unconscious spending can give you back control and help improve your long-term savings potential."
