Police said the six Liverpool men were ruthless and petrified their victims in 23 robberies between 2008 and 2015.
Ian Stewart, Kieron Whittle, John Stewart, Alan Lea, Shaun McDonald and Gary McNeill were sentenced to between 12 and 16 years in prison.
All pleaded guilty at Liverpool Crown Court to conspiracy to commit robbery.
Police said the gang wore masks and either used "brute force" to force their way into premises or removed roof tiles to allow them to drop down through the ceiling.
Most of the raids - which happened in Sefton, St Helens, Wirral, Liverpool, Warrington, Neston, Birkenhead, Bootle, Southport, Hull and Sutton - occurred when staff were either opening or cashing up.
The gang members were given the following sentences:
Det Insp Mike Dalton of Merseyside Police said: "This gang enjoyed a criminal lifestyle on the back of the misery of many decent, hard-working people who were simply doing their job when these men burst in and changed their lives forever.
"This gang was completely ruthless in what they did.
"They did not care who they harmed or what damage they caused as long as they got the money."
He said: "Innocent members of staff who were petrified at the time have remained too traumatised to return to work.
"A young mum was robbed of the enjoyment that having a young baby brings.
"Another who had a baby long after the robbery feared the stress she still felt could harm her unborn child."
A gang of armed robbers who stole up to £1.5m in a series of bank and post office raids in Merseyside, Cheshire and east Yorkshire have been jailed.