It you take care of the pennies...
The average person thinks they have pounds 1.61 down the back of their sofa, while two-thirds of us regularly find loose coins, according to Halifax.
Pockets, bags, and cars are also common places to mislay money, researchers found.
Desk drawers usually contain the highest amount of change. On average, people believe they have pounds 17.69 lying around.
When it comes to picking up money in the street, most would pick up no less than 50p, unless it was a 1p coin and could be lucky.
ICM surveyed 2,029 people for Halifax between July 29 and August 1.