Royal Mail has received a fine of more than £5 million due to missing delivery targets on both first and second-class deliveries by a "significant and unexplained margin".

A report by Ofcom shared that Royal Mail had only delivered 73.7 per cent of first-class mail on time during the 2022/23 financial year.

This was at a time when it was hit by 18 days of strikes by frontline workers.

It added that just 90.7 per cent of second-class mail was received on time.

Under Ofcom's rules, Royal Mail has to deliver 93 per cent of first-class mail within one working day and 98.5 per cent of second-class mail within three working days.

In the end, a fine of £5.6 million was dished out, Sky News reports.

What did Ofcom say about Royal Mail delivery targets?

A statement from Ofcom on the delivery targets said that by it falling under expectation it had caused "considerable harm to customers".

They said: "Even after adjusting Royal Mail's performance for the impact of industrial action, extreme weather and the Stansted runway closure, its first and second class performance was still only 82 per cent and 95.5 per cent respectively.

"This means that Royal Mail breached its obligations by failing to meet its targets by a significant and unexplained margin. This caused considerable harm to customers, and Royal Mail took insufficient steps to try and prevent this failure."

The fine Royal Mail received was reduced by 30 per cent to reflect the company's admission of liability and co-operation.

Oxford Mail: Ofcom said Royal Mail not meeting targets had 'caused considerable harm to customers'Ofcom said Royal Mail not meeting targets had 'caused considerable harm to customers' (Image: PA)

In response to the report by Ofcom a Royal Mail spokesperson said: "We are very disappointed with our quality of service performance in 2022-23 and acknowledge Ofcom's decision today.

"Last year was uniquely challenging for Royal Mail. Quality of service was materially impacted by the long-running industrial dispute which included 18 days of strike action.

"Quality of service is extremely important to us. We take our commitment to delivering a high level of service seriously and are taking action to introduce measures to restore quality of service to the level our customers expect."