Alliance Healthcare UK brought in extra staff to help recover services after an IT system problem last week caused disruption to deliveries over several days.
The technical issue was fixed at the beginning of this week and twice-daily deliveries are expected to be resumed in all areas by the end of today (14 September), said the company in a statement.
"Following an air conditioning outage at Alliance Healthcare UK on 7 September 2017, which caused service disruption across our network, we can confirm that the faults have been fixed, and our IT system has been fully operational since Monday 11 September 2017."
"We offer our customers our sincere apologies for the inconvenience caused, and thank them for their support."
Teams at Alliance Healthcare have been working around clock to process and pick orders, said the company. "Patient safety is always our main priority. To that effect, we have added 100 personnel to our service centres, so we can process any remaining orders as quickly as possible."
Customers are advised to order normally from Alliance Healthcare UK, while an emergency order process remains is in place for any urgent orders.