Courts around Australia have agreed to apply uniform rates when applying interest to debt. They will move from a practice where the Chief Justice of the Supreme Court in each state sets a rate for the courts in that state to a standard national formula based on a margin over the cash rate.Interest payments are an issue in many commercial cases, such as those involving disputed loans, breach of contract and damages."If there is money owed, interest is in play," said Greg Young, a partner at Forbes Dowling Lawyers.Young said that in most, but not all, cases where bank and other financial institutions were involved, financiers could rely on the interest rate in the credit contract. But there were many other types of transactions where no interest rate was set.Young said: "When matters go to court it could be months or years before people get the money they are owed. Interest can end up being a very large part of the claim."The new interest formula is in two parts: a rate that applies from the due date of a debt to the date of judgement; and a rate that applies to payments that are late after the date of judgement.The pre-judgement interest rate will be the cash rate plus four per cent, re-set on January 1 and July 1 each year. The post-judgement rate will be the cash rate plus six per cent, re-set on January 1 and July 1 each year.Young said: "This is a good move. Uniformity is desirable."