rob the till

or[have one's hand in the till] {v. phr.}, {informal} To steal money in your trust or for which you are responsible. * /The supermarket manager suspected that one of the clerks was robbing the till./ * /Mr. Jones deposited one thousand dollars in their joint savings account and told his wife not to rob the till./ * /The store owner thought his business was failing until he discovered that the treasurer had his hand in the till./