"As announced in August 2014, we are withdrawing our 0845 helpline telephone numbers.

Between 8 and 11 December 2014 we will be taking our 0845 numbers out of service, after which customers will only be able to use our 03 helpline numbers.

Customers who call a 0845 number after it has been taken out of service will receive a message telling them that calls to HMRC are no longer dealt with on that number. They will be given the new 03 number, and the call will then terminate.

Customers can find our helpline telephone number on our contact us page.

For most customers, an 03 number is cheaper to call than an 0845 number, and it is government and Ofcom policy is to use 03 numbers.

Read more about call charges on the Ofcom website."


https://www.gov.uk/government/news/withdrawal-of-hmrc-0845-telephone-numbers