So, like some others on here I was stumped by the new VAT agent account not showing my clients. This is what happened:
I moved home and wanted to update my address. Was informed can only update address if I create a new VAT agent account and from there I can link my exisiting agent account and all my clients would appear in the new account. I did all of this and to date no clients have shown. This was back in November.
Finally got a call back from a MTD agent and was informed this:
I can keep all my clients in my existing agent account. As the existing and new agent accounts are linked when I submit a VAT return through my software I will need to put in the new agent account credentials but the return will still go through to HMRC even though there aren't any clients in there as it is linked to the original agent account.
If I want to change the address but not have two logins just send in a paper 64-8
Hopefully this post helps others in what seems to be a complete faff of a system. Why you cannot just update your address for VAT online I do not know!