The question is in the title, when an estate is built and prewired for BT (with BT sockets) either by BT or the developer I am guessing each home is connected to the exchange some how...

... Other than connecting the e-side and d-side in the exchange (which the tech does from outside the property) what exactly does he need to do inside the house to get the line connected up?

We all know the £124.99 charge for this work is nothing short of a rip off, as I have a tech coming out tomorrow to connect my home yet the line has already been activated in the exchange as the number now rings but not into my house - so really what I want to know if what he will actually do tomorrow to connect it and how without getting too technical it works and what he does...

Cheers

There should be no work inside the house - BT will have run cables to the master socket and the builder should have correctly wired extensions from there (provided the electrician knew his stuff).

When the new occupant asks for service, BT connects the pair from the local street junction box back to the exchange (that may involve a fair amount more work) and, as you say, an engineer then needs to do the final connections at the exchange.

In other words, BT invests in the local cabling to the new premises on the assumption that someone will pay for a connection in due course so they can start to recoup their investment.

Heinz,

Thanks for the info much appreciated

The tech came to the house and stuck some device in the master socket, went outside and did something while it was in, then when he came back all was working...

All in all it took 10 minutes and more so from outside wherever he went in the van which I am assuming was an exchange or something. And your right BT charge the £124.99 to cover the initial work when the estate was being built, a little on the high side in my opinion however as its also prewired for sky and I have sky+ they sent me a form as they will refund the cost if I take sky talk and broadband from them

The Openreach charge ex vat is £88. The rest is vat and the margin put on by the retailer.

if you feel thats high, they could charge on an individual basis. £60 per M for cable in footway duct, £15 in grass, £150+ per M across carraigeway.
though as you say, not a problem as sky are footing the bill.