Troubleshooting common ASA problems

I can sign in, but I cannot see the client I need

First confirm you are in the ASA, not the older HMRC online services for agents account — HMRC's own sign-in guidance flags this as a frequent cause of confusion. Then check whether the client is registered for MTD yet. Client records typically appear in the ASA once the client has been registered for MTD; pre-MTD Self Assessment records remain in the legacy account.

Only some clients copied across

This usually means the firm has more than one legacy HMRC online services account or Self Assessment agent code, but only one was linked to the ASA. Repeat the add-authorisations process for each relevant agent code and reconcile client counts between the old account and the ASA.

I expected a client list with names

That is normal. The ASA shows which Self Assessment agent codes have been added, not a named list of clients in that authorisation view. For MTD purposes, firms normally search for an individual client by UTR once the client is in MTD.

We added the authorisation, but the client still is not in MTD

Authorisation and MTD sign-up are separate. After authority is in place, someone still needs to complete the client's MTD sign-up journey client by client.

The digital handshake has expired

HMRC's link lasts 21 days. Create a fresh request in the ASA and send the new link. Check status of requests from the last 30 days in the ASA.

We lost access after another firm got involved

A client can only have one main agent at a time for MTD for Income Tax. If the client appoints a different main agent, the existing main agent loses that access. Supporting agents can coexist, but with narrower permissions.

MFA is causing access issues

HMRC is introducing MFA for agent accounts in stages. Testing expanded during April and May 2026; MFA will apply to all agent accounts once testing is complete. Prepare early: individual staff credentials, at least two administrators, and check whether old MFA settings are already attached to the account.

Related: ASA setup · Adding client authorisations