This is copied and pasted from the autoresponder that customer.services@orange.co.uk is currently sending out...

Whoops, due to issues beyond our control we are currently unable to handle your email query. If you need to contact us by calling us on 07973100150 from a landline (landline calls are charged at local rates if you're a BT customer, but if you're with another provider it may cost more so do check). You can also contact us whilst you're abroad on 07973100150, where calls are charged at international rates.

I didn't know Orange had arranged for BT to charge 07973 calls at "local rates"..  :'(

They haven't.  It's yet another "misleading price indication".

Let the ASA know.

BT charges 07973 calls at fm4 rate which, for most* residential cuistomers will means 13.1p call set-up fee plus 11.576p/minute weekdays, 6.47p/minute weekday evenings and 3.406p/minute weekends.

* For those on Friends & Family Mobile, the per minute cost is 7p at all times (they save weekday daytimes, pay slightly more weekday evenings and lose out bigtime at weekends - paying more than double).

Heinz wrote on Aug 8^th, 2012 at 10:31am:

BT charges 07973 calls at fm4 rate which, for most* residential cuistomers will means 13.1p call set-up fee plus 11.576p/minute weekdays, 6.47p/minute weekday evenings and 3.406p/minute weekends. * For those on Friends & Family Mobile, the per minute cost is 7p at all times (they save weekday daytimes, pay slightly more weekday evenings and lose out bigtime at weekends - paying more than double).

Heinz, you appear to have fallen into the same trap as abusers of 084 phone numbers by quoting BT non-discounted ("standard") rates when in fact there are "discounts" for the call types in question. The quoted Call Set-up Fee is that which applies to BT discounted tariffs whereas non-discounted ones pay 3.1p.

fm4 calls from BT Calling Plans, of which most BT residential customers are subscribed to, cost 11.3 pence per minute during the daytime and 5.3 pence per minute in the evenings. Daytime and evening periods apply seven days a week; there is no separate weekend rate for mobile calls.

Heinz wrote on Aug 8^th, 2012 at 10:31am:

* For those on Friends & Family Mobile, …

BT Friends and Family Mobile has now been withdrawn.

Rates for calling mobiles from landlines will continue to be reduced over the coming years as the phased reduction in the termination rates paid by landline originators come to be passed on to callers.

They normally say something like

"The only way you can remove a bundle is by calling customer services on 150 from your handset or 07973 100 150 from a landline and speaking to a Customer Services agent (call charges may vary)."

http://help.orange.co.uk/orangeuk/support/personal/484373/3

But heres another example of where they claim its charged as a local call.

"For Orange subscribers: If you have pay as you go, you can dial 450 from your phone (at £0.25 per call) or 07973 100 450 from UK landline (local rates apply). If you have pay monthly, dial 150 from your phone or 07973 100 150 from a UK landline (local rates apply). "

http://orange.summeriscalling.co.uk/gbr_ee_orange/faqs.html

Checking their main contact page they say

"Calls are free from an Orange pay monthly
mobile. Charges from Orange pay as you go,
landlines or other networks may vary"

http://help.orange.co.uk/orangeuk/support/personal/contacting-us/paym