A foreign domestic worker would wait until her employer's elderly wife was asleep or watching television before stealing her ATM card.
Eka Nur Indah, who did this on dozens of occasions, withdrew more than $40,000 in total, which she spent on beauty treatments, mobile phones and jewellery.
Yesterday, the 26-year-old Indonesian was sentenced to one year's jail after pleading guilty to 18 theft charges involving $18,000.
Fifty-three other charges - mainly for theft - involving the remaining amount were taken into consideration during sentencing.
The court heard that the maid had discovered her employer's 76-year-old wife had written the personal identification number for her ATM card in a notebook.
She then decided to steal the card to withdraw cash and make unauthorised Nets purchases.
Deputy Public Prosecutor Marshall Lim said: "The accused knew the victim kept her ATM card in her bag, which is kept by her bedside."
On June 9 last year, Eka took the ATM card from the woman's bag. She withdrew $1,900 from an ATM near her employer's Yishun flat and then put the card back in the bag.
Between June 9 and July 18, she stole the card 21 more times.
Eka withdrew between $300 and $1,000 each time, the court heard, and remitted some of the money home. Her crime spree came to light when her employer's son, who was making some fund transfers using his mother's account, noticed that money had been withdrawn on a regular basis.
The 49-year-old man checked with his mother, who confirmed she did not make the withdrawals. He made a police report on July 18. Eka has not made any restitution.