Employee - Authorised signatory

How do I become an authorised signatory (and contact for queries on the phone) as an employee? Form 53 doesn't seem to apply as I'm not an agent.

Hi,
Are you looking to become an authorised person in relation to the VAT affairs of a business or is it for another tax?
Thank you.

Yes, VAT. HMRC seem happy I can answer all the security questions for any other tax, but I can't get them to talk to me about VAT. When I've asked on the phone before no one has been able to tell me how I become authorised.

Hi,

If you are an authorised employee for the business then you can speak to us on the VAT Helpline as long as we pass you on security. Being authorised in this sense means that your business are happy for you to talk to us
If you want to become authorised in terms of being able to write in to us then you can become authorised using a 64-8 form. Please see below:

Authorising an agent to deal with your tax affairs

Thank you.