HMRC has recently introduced three 0300 numbers.

The Child Benefit helpline is now 0300 200 3100, having changed from 0845 302 1444. The Guardian's Allowance helpline was 0845 302 1464 and has changed to 0300 200 3101. The textphone for both of these are now 0300 200 3103, which has replaced 0845 302 1474.

Dave wrote on Apr 25^th, 2013 at 9:41am:

HMRC has recently introduced three 0300 numbers. The Child Benefit helpline is now 0300 200 3100, having changed from 0845 302 1444. The Guardian's Allowance helpline was 0845 302 1464 and has changed to 0300 200 3101. The textphone for both of these are now 0300 200 3103, which has replaced 0845 302 1474.

So far HMRC only seems to have converted benefit lines to 0345 and is deliberately obstructing all progress towards the use of 03 for its various tax enquiry lines.  In addition it continues to actively block calls to the 01 alternatives to these 0845 numbers from UK landlines but not from UK mobiles.

Perhaps an FOI requesting copy of any documentation that shows where HMRC agreed with its telco partner to accept calls to its UK 01 numbers from UK mobiles but not from UK landlines might proved interesting.

See the main thread discussing this issue at http://www.saynoto0870.com/cgi-bin/forum/YaBB.cgi?num=1359720710