A soldier fraudulently withdrew more than €13,000 in cash when Ulster Bank experienced a computer failure.
Thomas Brannigan (30) made 45 withdrawals from an ATM in Tallaght on one day in June 2012.
Due to a glitch in Ulster Bank's computer system, he was able to take a total of €13,250 from his account, even though he had only €500 in it.
A court heard that Brannigan is repaying the money, and so far has handed back €3,500.
His lawyer, Gabby Deane, said he is also attending Gamblers Anonymous.
Judge John Lindsay adjourned the case to November, to allow Brannigan to continue to repay the money.
The defendant, of Parkhill Close, Tallaght, admitted before Tallaght District Court to more than 40 counts of theft.
Gda Keith Gorman said Brannigan stole a total of €13,250 from Ulster Bank on June 22, 2012 when a computer failure meant customers could withdraw cash even if their accounts did not have sufficient funds in them.
Gda Gorman said Brannigan used his ATM card to withdraw small amounts of cash, €250 and €300 at a time.
The withdrawals were all from the ATM machine at Dunnes Stores, Kilnamanagh Shopping Centre.
The court heard Brannigan had never been in trouble before.
Gda Gorman said he believed the thefts were "opportunistic".
He said Brannigan did not make any attempt at deception, as he used his own ATM card and took the money from his own account.
The court also heard he was very cooperative with gardai.
Ms Deane said Brannigan was eager to pay back the money he stole, but would need some time.
She said he works in the Defence Forces and could lose his job if a conviction is recorded.
Ms Deane also said that Brannigan is supporting a nine-year-old child.
A court previously heard Ulster Bank has issued criminal proceedings against a number of people who failed to pay back money withdrawn fraudulently while the bank was experiencing a software failure.