I'm here to provide you solutions so you can your client in your QuickBooks Online Payroll account, @aejal.
Before we start, can you share me with more details about the error your client is getting when creating his login? Any additional info would help me in sorting out the issue.
If your client couldn't create his new Intuit account or sign in if he already
have one, it's possible that there's an issue within his browser. Let's perform some basic troubleshooting steps so we can address this concern and add him as a user.
To start, ask him to open the email invite in a private window. Doing this will help us in isolating the issue. Also, using this mode wouldn't track his browser history. Just press the following short cut keys to access it:
- Press Ctrl + Shift + N (Google Chrome).
- Ctrl + Shift + P (Firefox).
- Control + Option + P (Safari).
If he's successful in creating his Intuit login, then you can ask him to clear the cache in his regular browser or use a different supported browser instead. his might be a temporary issue with QuickBooks and the current browser that you use.
I've also added some articles below that will help in managing your users in QBO Payroll. This also includes the user limits, how they affect your account, and what to do if you exceed your limit.
Keep me posted if you need anything else or if you have other questions about managing a user in QuickBooks. I'll be here to help. Have a great weekend.