I have been looking further into this and the quality of information given out seems very variable. See the two email replies from ADSL24 and Plusnet below:

ADSL24 said:
In relation to the FTTC service ...its a guaranteed service from BT wholesale, For example they guarantee 15mb sync minimum with minimum 12mb throughput for customers on Fibre business packages and minimum throughput of 8mb for Fibre home customers.
So BT will not offer the Fibre service if your speed estimate is below 15mb sync....however its been unofficially lowered to 12mb sync.
We as an ADSL reseller have the ability to place a fibre order for a customer and have an installation engineer despatched to your premises and then it will be his discretion as to whether he installs the Fibre service or not.

Now we can normally place an order if the Fibre speeds are estimated as being as low as about 10mb in some instances ...any lower than this ...and the chances for successful installation are close to null.

This does not really confirm what James posted about the lowest speed for a fibre connection.

Then we come to Plusnet :

Plusnet wrote by email:
Unfortunately we would only be able to provide fibre broadband broadband if the estimate was 15Mb or higher as these are the conditions put in place by our supplier. We have no way to work around this policy as the order would be automatically rejected based on poor speed estimates and I would assume that this would be the case for any BT based broadband provider. The only exceptions would be fibre broadband providers that do not use BT's network, such as Virgin Media.

Well that did not compute as Plusnet seem to accept orders online for sub 15Mb lines so I phoned them and they apologised and said after conferring that they would offer a connection down to 7Mbps which seems more realistic.

In reply to a post by Adsl24:

If you have any questions about our service please do just ask and I'll advise.

James can you or anyone help with this query ?
Someone round the corner from me cannot get an indication that he has FTTC available at any speed. Its as if the BTW checker has a blindspot. He has a stable ADSL connection at the moment and syncs at around 2.5Mbps as I do. All the other houses in the road show fibre availability at 13.2Mb. We are all connected to a cabinet in the next village.

So my question is how the devil do you get BT to update their database to give this line the same service as everybody else around. It seems a bit extreme to get another line installed just to get a result from the Broadband checker.

Thoughts or advise anyone ?

Normally the checker will show nothing if Openreach records deem the line is too long to receive 2 Mb or over (not 15 Mb or over), so they must think there is no chance of it getting the FTTC service.

I've updated my colleague who replied to you - as we can indeed accept orders for any estimation over 2 Mb, ie as long as FTTC is showing on the checker, we can place an order.

If you PM me the address and if possible a line number I can query with Openreach, but no guarantee they will do anything.

I've noticed loads of errors in the spread sheet data, now I can only assume that this data is drawn from BT's records, which of course can mean that errors are present in the BT Wholesale checker.

Does the spreadsheet data show your connected to the same cabinet as other people who can get FTTC in your street?

We will accept and provision any line that shows FTTC is available at 2 Mb or higher. So no problem at all and we have many customers live already who had a <15 Mb estimation. We've never had a failed FTTC installation yet and in 99% of cases the speed is higher than estimated.

ADSL24 said :
If you PM me the address and if possible a line number I can query with Openreach, but no guarantee they will do anything.

Thanks James PM sent.

In reply to a post by Adsl24:

We've never had a failed FTTC installation yet and in 99% of cases the speed is higher than estimated.

Quite so. My speed estimate was 10.7Mb and this meant that some ISPs would not offer service, but I went with ICUK and connected at better than 38Mb. It was a new FTTC cabinet and I was told to expect the speed to drop as more people connected to it. A month later it is still running at well over 30Mb.