I have a BT landline  and  am signed up with 181815  and  Primus saver option 2.
I have a problem with PSO 2 . On a couple of recent statements they show a large amount (£16) billed to me on  -   Directory Enquiries DQ11     44118501.  This no. is unfamiliar to me and when I pointed out to them that as far as I know no no. in the Uk starts without a zero in front,  their answer was  - our records show....blabla.. Anyone clarify please.
 PS  I phone Thailand once  a week using the prefix  08442001010

I look at the number "44118501" and see that the last six digits could be a directory enquiries service; 118501. See Crosby Directory Enquiries.

If Dave's answer is correct simply go online free of charge to:
http://www.thephonebook.bt.com/publisha.content/en/search/international/index.publisha
for the same service

I am a subscriber to PlanetTalk/Primus service. I am frequently getting billed on a no. I do not recognise. It apears on my itemised bill as   
  Directory Enquiries DQ 11    44118501
I have contacted them before but they insist I made the call. I would not use D.E. by phone only by i/net.
  In addition I thought all phone nos. in UK had to start with a zero?  Any thoughts please.

hhmikehh wrote on Sep 29^th, 2012 at 9:50am:

I am a subscriber to PlanetTalk/Primus service. I am frequently getting billed on a no. I do not recognise. It apears on my itemised bill as      Directory Enquiries DQ 11    44118501 I have contacted them before but they insist I made the call. I would not use D.E. by phone only by i/net.   In addition I thought all phone nos. in UK had to start with a zero?  Any thoughts please.

You asked same question and got answers a fair while ago. ;)

See http://www.saynoto0870.com/cgi-bin/forum/YaBB.cgi?num=1281002051

Its this number prefixed by 44    http://www.crosbysystems.com/crosby-directory-enquiries/118-501-international-directory-enquiries/

The number is 118501, the digits 44 being the international code for the UK.

There are numbers and access codes that start with 1. A few years back, six-digit directory enquiries numbers beginning with 118 were introduced.

I put 118501 into Google and the first link that came up was a thread on MoneySavingExpert.com started by someone who found entries for this on their bill.

Although the OP didn't bother to reply, suggestions were made that this could have come about due to mis-dialling of the 18185 prefix which is used by a call provider. Basically, if the second digit is missed out it becomes 1185. If one then goes on to dial a number with an STD code beginning 01, the number then dialled becomes 118501. So if the number started 01234567, then the number 118501234567 would actually connect to 118501.

Could this be a possibility here? Has someone in your household registered the number with 18185?

bigjohn wrote on Sep 29^th, 2012 at 10:06am:

You asked same question and got answers a fair while ago. ;) See http://www.saynoto0870.com/cgi-bin/forum/YaBB.cgi?num=1281002051 Its this number prefixed by 44    http://www.crosbysystems.com/crosby-directory-enquiries/118-501-international-directory-enquiries/

Thanks for pointing this out bigjohn. I have joined the thread hhmikehh started today with the one from two years ago.

It is interesting that the OP says he is signed up with 181815 (sic) which tends to suggest that this may be misdialling and that it may have gone on for a few years. It's perhaps false economy to use 18185 if the prefix isn't being dialled correctly.