Royal Mail has apologised after late deliveries left many school pupils waiting anxiously on exam results this weekend.
The company received a formal complaint when a number of Northern Irish grammar school entrance results failed to arrive on Saturday.
14,000 of the papers were due to be delivered, but Royal Mail admitted that a small number did not arrive with normal deliveries due to a sorting error.
The delays occurred in the Craigavon area of the country, and were eventually delivered. However, the post-primary transfer consortium is asking for a detail explanation of the mistake.