Hi, how do I link my newly installed QB on my iPhone with my existing QB account on my Mac as when I sign in with the same details on my phone it won’t link up?

Let's try resetting your password on a web browser, Jonezy73.

This is to make sure that your credentials will sync on the mobile app. I've got the steps to do it:

Just a heads up, you need to have access to the email you used when you signed up for QuickBooks Self-Employed.

1. Log in on a web browser: selfemployed.intuit.com.
2. Click the Forgot your User ID or password hyperlink.
3. Enter your phone number, email, or user ID.
4. Click Continue.
5. If you used your email address or user ID to verify your account, you'll receive an email with a password reset link.

Then, reset your password. Afterward, let's try logging into your mobile app.

If the same thing happens, it would be best if an agent will take a look at your account. To do that, you'll have to reach out to our Phone Support team. 

1. Click the Assistant button.
2. Enter Talk to a human.
3. Enter Data sync as your keyword.
4. Select I still need a human.
5. Select Chat.

Please let me know as to how things work on your end. Stay safe!