David Mason, 18, and a boy of 13 who cannot be named, are accused of arming themselves with a machete and stealing cash and pizzas from one delivery driver, before they attacked the elderly man in his Warrawong home.

The pair allegedly struck again a week later, stealing another pizza delivery driver's money and mobile phone.

The 13-year-old was arrested on Tuesday and Mason on Wednesday.

Both teens were charged with two counts of armed robbery and one count of aggravated breaking and entering.

The 13-year-old appeared in Campbelltown Children's Court and did not make a bid for bail.

Mason did not apply for bail in Wollongong Local Court yesterday and it was formally refused.

Police claim the teens robbed the first delivery driver in Dean Street, Warrawong, just before midnight on February 9, and made off with cash and pizzas.

Just hours later, the pair allegedly broke into an elderly couple's home while they were asleep.

Police claim the couple, aged 88 and 79, were confronted by the pair, who demanded money before punching the man in the face.

They allegedly rummaged through a few drawers, stole some cash and then fled.

Less than a week later, the teens allegedly confronted and robbed another delivery driver in Lake Heights, armed with a machete.

Mason is set to reappear in court on May 1. The 13-year-old is to appear in Port Kembla Children's Court on Monday.