The sums he got away with varied from $8 to $270, and total almost $1500.
He also stole a Salvation Army money box with $40 inside it on September 26.
Police last month warned of a man posing as a Hororata farmer who approached shoppers in mall car parks and asking for money so he could fill his car with petrol and drive home.
He appeared in court last month on 27 charges.
But after media publicity, more victims came forward to police saying they had also been taken in by Barwell.
Sergeant Greg Hume said some of them said Barwell had scammed them even after he had been in court.
Christchurch District Court was told today that Barwell was due to be sentenced on other matters next week.
Now, he will have to stay behind bars until he is sentenced in January on all matters.
Judge Paul Couch warned him that given his "extensive history" of dishonesty, the starting point for sentence would be a "significant period of imprisonment".