Full fibre installation: what happens on the day.
An engineer brings fibre from the nearest pole or underground duct, drills a small hole through an outside wall and fits a small box called an ONT (optical network terminal) inside. Your router plugs into the ONT. Openreach says most installations take one to four hours, and someone over 18 must be at home.
What the engineer does
Fibre runs from the nearest connection point, overhead from a pole or through an underground duct.
A small hole is usually drilled through an outside wall to bring the cable in.
A small box is fitted inside where the fibre ends. It needs a power socket and connects to your router.
The engineer tests the line before leaving.
Before the engineer arrives
Pick where the ONT and router will go: central, near a power socket, not in a cupboard if you can help it.
Make sure the engineer can reach the outside wall and the inside spot.
In a flat or rented home you may need the landlord’s or building owner’s permission for work in shared areas.
Your old phone socket is no longer needed for broadband; phones move to Digital Voice through the router.
Check if full fibre reaches your address
Full fibre installation: common questions
How long does full fibre installation take?
Most Openreach installations take one to four hours; longer if ducts are blocked.
Do I need to be at home?
Yes. Someone over 18 must be there to give access and agree where the equipment goes.
Will they drill through my wall?
Usually, a small hole in an outside wall to bring the cable in.
Can I move the ONT later?
Ask your provider; moving it may need another visit and can cost extra.
Facts checked 27 October 2026 against Ofcom rules, Openreach and provider terms. How we make money →