Economic conditions in 2020 brought an end to more than a decade of gradual improvement in late payments times, a new survey shows.

According to the latest illion Australian Late Payments Report, late payment days worsened by 10 per cent last year.

Payment times between big business increased from an average of 13.9 days past the due date to 15.5 days.

When it came to big businesses paying small businesses, payment times increase from 13.2 days past the due date to 13.4 days.

Small businesses were better payers, with an average of 13.1 days past the due date when it came to paying big businesses and 9.7 days when paying other small businesses.

During the December quarter, 28 per cent of businesses were late making payments.

Payments times in the manufacturing, wholesale and retail sectors improved as the year went on but got steadily worse in the construction sector.

The state where the deterioration in payment times was worst last year was Tasmania, with late payment days worsening by 22.4 per cent.

Victorian businesses did better than the national average, despite the extended lockdown there.