The usual way is a letter of demand and then, if payment is not received, by issuing a Court proceeding. This could be in the Magistrates’ Court (for amounts up to $100,000), County Court, or Supreme Court. The defendant has between 10 and 21 days after service (depending on which Court) in which to pay or compromise the claim, or take steps to defend the proceeding. If the debt is not genuinely disputed, you could serve a statutory demand (and affidavit in support) on the registered office of the company. If they don’t pay or reach an agreement with you, or apply to set aside the demand, within 21 days the company is deemed to be insolvent and a Court proceeding can then be commenced to wind up the company.