Isle of Man Post is warning its customers could be affected by industrial action in London today (Friday).
The Communications Workers Union has also announced action in Edinburgh, Bristol, Darlington, Stoke-on-Trent, Plymouth, Norfolk and Essex.
Post is being forwarded as normal but it may be delayed if it is being sent to an affeted area.
Normal service will resume on Saturday.
Revised plans for Lord Street bus station development
Height of premises would be lowered under changes
Consultation for new National Infrastructure Safety Bill
Department of Home Affairs wants public feedback
Steam Packet cancels Friday evening sailings
It is due to adverse weather forecast
"Ramsey and District Cottage Hospital is not at risk of closure"
Manx Care insists relocation of services is only temporary