The Post Primary Teachers Association says the consequences of persistent errors in the Novopay system are spreading to other Government departments.
The $30 million system has been plagued with errors since it was introduced in August, with underpayments, overpayments or no payments at all to some school employees.
The PPTA said on Sunday it is becoming apparent that payments are not being made to agencies like the Accident Compensation Corporation and Inland Revenue Department, even though they are listed on payslips as being paid.
President Robin Duff said that could affect people's access to entitlements like family support payments.
He said people may find it difficult to gather the necessary information to have such decisions reviewed, if their payslips are not accurate.