This is old, but believe it still applies
If any of the following changes are made to an End Users PSTN service, the
ADSL service should NOT be ceased:
* Where the customer wants a renumber
* Where the customer wants to change tariff (i.e. between Business and
* Where the customer wants to change the Account Holder's name for
* Deed Poll
* Business Name Change
* Where a Business Customer wishes to change the location of the PSTN
(and ADSL) within the same building (in effect a Shift, but may be a
* Where the customer requires a change of Billing Address, with a
* Where the customer is changing to / from Calls & Access, or from one
Calls & Access provider to another.
In all other circumstances where there is a change to the PSTN service, the
ADSL Service will be ceased.