Police in Craigavon say there has been a "smash and grab spree" with three attacks across the district in the past few weeks.
They think the thieves may have had prior knowledge of the cash lift and are appealing to local people to be vigilant.
In a social media post, they point out that each attack followed a similar pattern.
"The victim withdraws a large amount of cash from a bank and takes it to their car. The window is at some stage then smashed, with the bag holding the money taken," they said.
"On each occasion, other items of value have been on show but ignored, leading us to believe that there is prior knowledge of the cash lift.
"If you regularly lift large amounts of cash, whether it be for wages, regular purchase orders, or whatever else - think about what patterns you're setting. If you use one branch, try using a different one and mixing it up. Go at different times, on different days where possible.
"If there's a certain route you use, vary that too. Different junctions, twice round roundabouts, that sort of thing. If you think you're being followed as a prelude to an attack or theft, drive to a police station or phone 999.
"Above all, never leave anything of value on show. It makes it far too easy for those who would take advantage."