Inland Revenue's current practice was to accept payment as being made on time if a cheque was mailed and postmarked on the due date.
Where a due date fell on a weekend or public holiday, an extension was given until the next working day. Provincial anniversary days were currently treated as public holidays.
Mr Stevenson said Inland Revenue was proposing to change its practice to the cheque payment being required to be received by the due date.
Provincial holidays would not longer be treated as public holidays, under Inland Revenue proposals.
Returns could currently be filed and tax payments made at Westpac branches. But Inland Revenue was proposing to make changes so Westpac would no longer accept returns and payments could only be made over the counter at Westpac, by cash or eftpos, he said.
The proposals were an attempt by Inland Revenue to ''encourage'' electronic payments. More than 70% of tax payments were made electronically and the tax department wanted to increase that percentage.
''Some individuals and organisations cannot easily make payment electronically. For example, people without internet banking and a number of small business owners and not-for-profit and sporting organisations with two signatories,'' Mr Stevenson said.
The changes would also compress the time available to file returns and post payments because recent changes to New Zealand Post delivery times meant payment would need to be posted well in advance of the due date to have any certainty of arriving at Inland Revenue ''on time'', Mr Stevenson said.
Inland Revenue had indicated it would try to not present post-dated cheques until the due date. However, it would also not be responsible for any dishonour costs if cheques were presented early and funds were not available.
''Anyone who pays by cheque will need to be careful they have sufficient funds available at the time they post the cheque.
''Penalties will be charged the day after the due date. Failing to meet the proposed deadlines will come at a cost.''
The only way to make payment by cheque on the due date would be to physically deliver it to an Inland Revenue office, which were not located in smaller towns.
Mr Stevenson said if the changes go through as proposed, taxpayers who were not willing or able to make payments electronically would need to file returns and make payment earlier, as they would no longer be able to tell the department ''the cheque's in the mail''.
It was understandable Inland Revenue would like to increase the amount of electronic payments but it needed to be careful doing so did not discourage voluntary compliance or add further costs for smaller organisations.
''Inland Revenue needs to widely publicise any changes before they become effective,'' Mr Stevenson said.
