OECD proposals to limit the amount of tax deductions companies can claim from debt-loading could see large New Zealand companies stung for up to $87 million in extra annual tax bills.
A spokesman for Inland Revenue said "a high level of debt does not necessarily indicate a problem with our current rules" and there were underling issues not captured by simple metrics.
"You could see a company with high debt levels, but that company may be having interest deductions denied under the rules, which is exactly how they are intended to operate," the spokesman said.
In addition, Inland Revenue said high debt levels were allowed if the debt-loading on a New Zealand subsidiary were similarly-loaded across the company's worldwide operations.
"This is because the high debt worldwide reflects that the company operates in an industry with high levels of commercial debt," the spokesman said.
How do the companies identified as being potentially exposed respond?
ANZCO Foods: A spokesperson said the company's CFO, described as the most appropriate person to answer questions, "is currently overseas and is unable to respond".
BP New Zealand Holdings: Did not respond.
Bunnings: A spokesperson said the company's interest:ebitda ratio had fallen below 30 per cent since the financial reporting date in question. They also drew attention to long-stated support for tax fairness from Richard Goyder, the managing director of parent Wesfarmers.
"People in communities are within their rights to say 'company XYZ is selling its products here and making its profits here but they are not paying tax, so what's going on?'" Goyder told the Sydney Morning Herald in 2014.
"My personal view is that the tax issue will become a bigger one for companies, and will go directly to their reputation. You are starting to see that happen now and, frankly, I think it should."
ExxonMobil New Zealand Holdings: A spokesperson put their particularly high percentage down to an unusually low ebitda due to inventory revaluations from fluctuations in oil prices.
"The inventory devaluations have been extreme events across the industry, and in a more stable price environment we wouldn't see such writeoffs , and would see a lower Interest/EBITDA ratio," the spokesperson said, noting the ratio for the 2015 financial year was 50 per cent.
Fairfax New Zealand Holdings: A spokesperson said the period being looked at was just before significant debt repayments and the proposed interest cap was "not an issue or concern".
"Our Net Interest:EBITDA ratio has fallen - and remains significantly below - the threshold," the spokesperson said.
"Fairfax takes all necessary care to ensure the correct amount of tax is returned in each jurisdiction in which we operate and we are transparent in our reporting on our tax affairs."
Farmlands Co-operative Society: Did not respond.
Foodstuffs North Island: Did not respond.
Fonterra Co-operative Group: A spokesperson said the company's financial position had changed since the period in question and an interest:ebitda cap was "not something likely to impact us at the thresholds being discussed".
Goodman Fielder New Zealand: Did not respond.
Haier New Zealand Investment Holding Company: Did not respond.
Ingram Micro New Zealand Holdings: Did not respond.
Powerco: A spokesperson did not answer question, but made minor corrections to ebitda figures calculated by Deloitte.
Ravensdown Fertiliser Co-operative: Did not respond.
Silver Fern Farms: A spokesperson said an upcoming capital injection, part of its takeover by Shanghai Maling, would see its interest:ebitda ratio drop well below 30 per cent.
Transpower New Zealand: Did not respond.
Two Degrees Mobile: A spokesperson said: "We have nothing further to add: 2degrees does not have a position on this because we do not see it impacting our business moving forward."
Vector: A spokesperson said they were unable to comment on the policy as it had yet to be formally circulated. "As you would expect Vector and its advisers maintain a regular and cooperative dialogue with the IRD on many matters. But we do not comment on the specifics of these discussions."
Z Energy Ltd:A spokesperson said their interest:ebitda ratio was unusually high in the period in question, due to oil-price fluctuations causing revaluations that bit into earnings. The company's ratio dropped in the next financial year to 18 per cent.
Z had yet to form an opinion on the policy, the spokesperson said: "If and when we do form a position it will be informed by what we think the right thing is for New Zealand. We believe companies should pay their full tax obligations promptly and transparently as a core part of doing business in New Zealand, and Z does."