Royal Mail aims to deliver to all addresses it has mail for, six days a week, however this is not always possible.
Local factors, resourcing issues, high levels of staff sickness absences and even poor weather conditions can all lead to postal delays.
Royal Mail outlined which UK areas may be adversely affected today, and apologised for the inconvenience caused to any customers.
In cases where mail is delayed, the postal service pledged to rotate deliveries to minimise the delay to individual customers.
Targeted support will also be offered to affected offices to address their challenges and restore service to a high standard.
UK areas affected by delays today
Hampstead DO (NW3)
Winterbourne DO (BS36)
Royal Mail also gave customers an update on its air, rail and road networks, as well as its mail centres.
In the last 24 hours, Royal Mail’s rail and road network services operated to schedule.
As for Royal Mail’s air network, the postal service shared: “Our air network operated to schedule over the last 24 hours, with one exception.
“Last night, an aircraft carrying mail from East Midlands Airport to Aberdeen Airport was delayed due to technical issues.
“As a result, some mail posted yesterday in the Midlands, north of England, Wales and Northern Ireland, for delivery in parts of North East Scotland, Orkney and the Shetlands may arrive later than planned.”
As for Royal Mail’s mail centres, not all mail was processed or despatched to schedule over the last 24 hours in Bristol. As a result, some mail may be delivered later than planned.
“Some mail posted in the BA, BS, GL and TA postcode areas, due for delivery today in other parts of the UK.”
In Northern Ireland, some mail posted in the BT postcode area, due for delivery in other parts of the UK, might arrive later than planned.