Deloitte Dunedin tax partner Peter Truman said most business owners would be focusing on getting back to normal, restarting operations and employing their staff.
However, they were probably making decisions now which would have tax implications down the track. Once those decisions had been made, the tax implications were impossible to change in the future.
The loss on destruction of buildings was usually seen as a capital loss and was not tax deductible.
"There is an exception to the general rule that applies where a building has been irreparably damaged and is unable to be used to derive assessable income - provided that the damage was not caused by the landlord.
"Where that criteria was satisfied, a loss on destruction will be available."
A loss on assets other than buildings was tax deductible. Assets should ideally be scrapped and disposed of by the balance date, Mr Truman said.
Insurance proceeds for an asset that was irreparably damaged were deemed to be proceeds on the sale of the asset. That could lead to depreciation being recovered if the sale proceeds exceeded book value or a loss if the proceeds were lower.
The cost of repairing assets so they were back to their pre-earthquake condition would be deductible, he said. Repairs that improved the asset were likely to be classified as capital expenditure.
Insurance payments for damaged - but repairable - assets were assessable and represented a net deduction off repair costs.
One of the more important areas was business interruption, Mr Truman said.
The proceeds of business-interruption or loss-of-profits insurance polices were assessable income.
The cost of relocating to new premises would be deductible where the principle purpose of the relocation was to maintain and preserve the existing structure of the business.
"The Inland Revenue Department argue that a move to larger or improved premises is capital expenditure and not deductible."
Payments made or received to surrender a lease on a premises were likely to be non-assessable or non-deductible, but each case needed to be reviewed according to specific facts, he said.
How staff were treated during this time also had important implications for employers, Mr Truman said.
Employers needed to consider the tax treatment of any ex-gratia payments made, such as assistance with temporary accommodation. The temporary accommodation payment should be considered when PAYE was calculated.
Many businesses would be having difficulty accessing business records to enable the normal tax compliance to take place - filing PAYE returns, GST and 2010 year-end returns due by March 31, Mt Truman said.
"IRD has indicated it will be lenient in genuine cases, which we have already seen."
Cash donations to approved charities would qualify for a tax rebate, up to certain limits, where made by an individual. Donors should check whether the organisation receiving the donation qualified.
"We have seen some employers promoting support through the 'payroll-giving' scheme, which immediately delivers employees the 33% tax rebate through a reduction in their PAYE.
"Businesses may also be able to claim deductions for cash donations made to approved charities."
Non-cash donations generally did not qualify, Mr Truman said.
Asked about the access to tax professionals during the trying time in Christchurch, Mr Truman said the "big four" accountancy firms were ensuring clients were being serviced from offices other than Christchurch.
Smaller accountancy firms might be having difficulty finding premises, but he was sure they would be all happy to take calls on their cellphones from clients needing help.
