Fresh milk supply in Western Australia has come under pressure as Coles had to source milk from its South Australian suppliers to stock its shelves across WA. The traditional holiday spike in demand for fresh milk was exacerbated by more people staying at home over the holidays due to travel restrictions. At the time it was operating with just eight of its contracted local suppliers, with two more joining on 1 January after fulfilling contractual obligations.

Coles has direct purchase agreements with 10 suppliers in the state and has toll arrangements with Lion Dairy & Drinks and Brownes Dairy who process and package Coles-supplied milk in WA. While reportedly Coles approached other processors for additional milk, rival processors claimed they had insufficient supplies, necessitating two tanker-loads of milk to be hauled the 2,600kms from Adelaide. According to Coles, the supplementary volume equated to about 8% of Coles brand fresh white milk supplied to WA stores over the two weeks leading up to Christmas.