"We are not trying to collect taxes due in previous years," commissioner general of Sri Lanka's Inland Revenue Department Mahinda Medagoda told a meeting of revenue officials in Colombo.
"We do not approve that and officers have been instructed not to do that.
Economic activity is expanding in those areas, but our network of offices is weak after a long war.
Medagoda said there was a need to start branch offices in Mannar in the north west and Amparai in the east, because people had to travel long distances to visit inland revenue offices.
He said businesses in the region were asking for advice on tax laws as they are not familiar with tax rules of the country during the war.
Some trade chambers have also asked the revenue office to conduct seminars and people needed advice on how to fill forms.
Parts of northern and eastern Sri Lanka was under Tamil Tiger separatists up to May 2009 when the leadership of the group was wiped out by the military.
Medagoda said a tax office