Royal Mail has said three staff at its Margate delivery office have tested positive for coronavirus.
An intensive clean has taken place at the site, as well as additional cleaning of key touch points and all communal areas, a Royal Mail spokeswoman said.
"We are temporarily not handing over our hand-held devices to customers to capture signatures," she said.
The spokeswoman said 18 staff were now self-isolating.
All staff have been briefed about social distancing measures, she added.