This is as a result of the downward pressure in global commodity dairy markets in recent months.
Commenting on the announcement, Jim Baird, Vice-Chairman and farmer director, said:
"Improvements in First Milk's business performance meant that we could delay a milk price reduction for January. Recent market developments will affect our customer pricing mechanisms, however, and we can only pay a milk price linked to our returns.
"We understand that this will be disappointing news for our members and remain completely committed to doing everything we can to reduce the impact of decreases in the market through our focus on quality and efficiency throughout our business, and through the development of our strong relationships with customers. Working together, we will deliver competitive returns to our members."