However, private operators such as Evri and DPD have been under strain too, with some customers of both carriers claiming to have received parcels intended for Christmas delivery well into January.
This is said to be partly down to private operators being inundated with work as online shoppers avoided the Royal Mail ahead of Christmas.
Evri has borne the brunt of the criticism, with some commentators believing its rebrand from Hermes hasn’t worked out as planned.
In this latest episode of the Last Mile Prophets Videocast, regular panelists Marek Różycki and Peter MacLeod offer their thoughts and analysis on the situation.