Changes to the Freeview signal in parts of North Yorkshire and Teesside means another retune is needed.
The changes will affect BBC TV and Radio services as well as HD channels from ITV, Channel 4 and Channel 5 for viewers reliant on the Bilsdale transmitter, which broadcasts BBC North East and Cumbria and ITV Tyne Tees.
Viewers in places such as Northallerton, Thirsk, Darlington, Middlesbrough and Hartlepool will be among those affected.
As a result, during the early hours of Thursday morning, Freeview is subject to a break in service.
From 6am viewers will be able to retune to restore any missing channels.
Sky, Virgin Media and Freesat are not affected by these changes.
Viewers who need asssistance should contact the Freeview advice line on 0808 100 0288. Alternatively, go to www.freeview.co.uk/tvchanges
The changes are indirectly linked to recent frequency changes in the North of England, with a relatively short notice decision to swap the frequencies of the two BBC TV multiplexes to improve reception in some areas.