Women confessed to lying about earnings and failed investments, with one admitting decanting expensive face cream into a cheap bottle.
The most shocking confession was from a man who said he had emptied his children's saving accounts to pretend the cash was a bonus after his own was cancelled.
Psychologist Andrew Kinder said: "In the current climate, concealing expensive purchases or unwise investments from those closest to us is likely to exacerbate the problem.
"Unburdening your financial transgressions, even anonymously, can be a crucial first step to taking control."
The annual AXA My Budget Day is next week, and is intended to get everyone into the habit of spending one hour a month or 15 minutes a week checking their finances.
Meanwhile, it was recently found that men are more likely to keep spending secret from their partners than women, contrary to the stereotype of shopping bags hidden in the wardrobe.
Research from fairinvestment.com showed that men spend 55 per cent more on the sly than women do.
Click here to run an energy price comparison, and see if you could be paying less for your gas and electricity.