Royal Mail has announced that deliveries in Norwood could face delays today.
The postal service said that customers in postcode SE19 could be impacted on September 8.
This is due to local factors, including "high levels of sick absence" and "resourcing" challenges.
The company, which operates six days a week nationwide, rotates deliveries in these instances to minimise the delay to individual customers.
On its website, the Royal Mail said: "In a small number of local offices, this may temporarily not be possible due to local issues such as high levels of sick absence, resourcing, or other local factors.
"In these cases, Royal Mail rotates deliveries to minimise the delay to individual customers."
The British postal service is providing targeted support to the Norwood offices to address their challenges and restore their service to the high standard.
This weekend, issues might also affect postcodes in Bicester, Clogher, and St Helens.