The youngster, who Australian TV channel 9News has nicknamed “Drew”, had argued with his mother about going to the Indonesian island.
Drew responded to the row by researching an airline that would allow him to fly unaccompanied, stealing the card details and booking a round trip.
He then proceeded to book a room at the All Seasons hotel after convincing his grandmother to give him his passport.
Drew told his family he was going to school before getting a train to Sydney airport, where he boarded a flight bound for Perth and then another to Denpasar, Bali’s capital.
Upon arriving at the hotel, he told staff he was waiting for his sister to join him.
He was only questioned once during his trip, at Perth airport, where staff needed to see ID to prove he was over 12.
Drew told the Australian news network: “They just asked for my student ID and passport to prove that I’m over 12 and that I’m in secondary school.
“It was great because I wanted to go on an adventure.”
He was able to take advantage of a loophole in flight regulations that allow unaccompanied children over 12 to travel without restrictions, so long as they can prove their age.
9News, which interviewed Drew and his mother for their programme A Current Affair, said the youngster stayed away from potential interference by taking just a hold bag, which he didn’t need to check in.
At immigration in Bali he told officials his parents were “waiting outside”.
For the next four days, Drew “partied”, according to the network, hiring a motorbike and trying beer.
After his school reported his absence, his family reported him missing but it was only when he posted photos and video of his trip on social media that his mother Emma worked out where he was and flew out to collect him.
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Emma said to 9News that she was: “Shocked, disgusted: there’s no emotion to feel what we felt when we found he left overseas.”
Emma added: “He doesn’t like the word ‘no’.”