Supply chain disruptions and the prospect of higher interest rates are being blamed for small firms having to wait longer to be paid.
Accounting and business advisory firm BetterCo said firms had typically been paid about 30 days late in the past 12 months, but that had crept up to more than 40 days over June and July.
In some cases, it had reached 60 days.
Managing director Vinay Iswar said small businesses across all sectors of the economy were reporting delays.
Several factors were at play, he said, including product shortages pushing up the costs for businesses and people holding onto their money or looking to direct that money elsewhere in anticipation of higher interest rates.
"Some have the money, but, from some of the conversations we have had, they are choosing to invest elsewhere either in property or other business start-ups," he said.
However, Iswar said those individuals were being a little selfish because it meant companies they owed money too were not getting paid and posed a risk to their cash flow.
"We're seeing [businesses] net working capital reduce, which basically means that if they were to go a month, two months without getting their money in from their customers... after a few months there actually wouldn't be any money left."
Net working capital is used to measure a firm's short term liquidity. It is the difference between a company's current assets and their liabilities.
Iswar said some firms were hesitant to put in measures to collect cash they were entitled to because they thought they could lose the customer.
"People do need to think differently other than just agreeing to get a client and saying 'oh, you're a big client so we'll delay your payment to the next month' because that's even more riskier."
He encouraged firms struggling with late payers to outline their expectations to them, shorten their payment terms to seven days, consider direct debit repayments, and make it easier to be paid.
"By changing your payment terms and switching to direct debit, you are offering your client convenience and protecting your own business."