Mr Sumaila said that filing annual returns of income from all sources was mandatory for all taxpayers.
According to him, the best form of compliance is voluntary.
Mr Ango urged employees to take deliberate steps to uphold the integrity of the service.
Mr Abdullahi pledged to give the necessary support to the new acting chairman.
Mr Sumaila said the service would not hesitate to enforce the laws against defaulters.
Mr Sumaila warned that FCT-IRS would not issue tax clearance certificates on WHT credits wrongly sent to other tax jurisdictions by the GIFMIS platform.
The agency said all taxpayers, particularly employers or agents in the FCT, were to file annual returns before the deadline.
Mr Abdullahi said tax officials required technical and verbal skills to effectively audit and interact with taxpayers including politically exposed persons.
The tax agency boss expressed concern about taxpayers’ poor level of compliance despite the huge number in the FCT.
A tax chief said the effort will make the FCT have the capacity to fund its budget solely through the IGR.
