Arrangements are being made to pay affected customers 'as soon as possible'
There is a problem with some payments of the fuel allowance due this week, according to the Department of Social Protection.
Lump sump payments were due and the problem affects those on the state pension, disability allowance, invalidity pension, contributory widowers pension, and the national fuel scheme.
The Department says the delay is being investigated.
It adds that arrangements are being made to pay affected customers 'as soon as possible'.