Alan Roberts, of Stowford Close, West Derby, targeted six stores between July and September this year including shops in Moreton, West Kirby and Crosby, on Merseyside.
He also struck at branches in Frodsham and Knutsford in Cheshire, Huddersfield, and in the Staffordshire town of Leek.
Liverpool Crown Court heard how during his spate of raids, Roberts stole thousands of pounds in sterling and foreign currency from till drawers and escaped with the help of an unknown getaway driver, The Liverpool Echo reports.
Prosecutors described how the 44-year-old repeatedly demanded for safes at the agencies to be opened but his requests failed because of time delay locks.
The court also heard how Roberts wielded a knife at staff at the Co-operative Travel store in West Kirby on July 18, while wearing sun glasses to hide his face and later made off with around £3,000 in cash.
On August 5, Roberts “terrified” staff at another Co-operative Travel in Crosby brandishing an imitation handgun and became “agitated and irate” when a travel consultant entered the wrong security code for the store’s safe by mistake.
Roberts’ final robbery was at a Thomas Cook branch in Moreton, on September 10. During the incident Roberts donned sun glasses and a bandanna and carried a knife.
He stole around £2,000 worth of sterling and US dollars.
He was arrested two days later and pleaded guilty to six robberies, one attempted robbery and four counts of possessing an offensive weapon.
He also admitted to possession of an imitation firearm with intent to cause fear of violence.
Sentencing Roberts for 10 years and eight months with an extended five years on licence, Judge Denis Watson, QC, told him: “You are a very dangerous individual.”
It was revealed that Roberts had twice previously been jailed for travel agency robberies.
Michael Bagley, defending, said Roberts had been “plagued by drugs throughout his adult life”.
Roberts claimed he had to try and pay off debts that were not his own, The Liverpool Echo reports.