The person who was our master admin left the company several years ago and we need to change master admin to another current user?

Do you have any access to the email address which he/she was using to login as Master Admin? It would be easier to self reset than submit some documents to clain the account.

Allow me to join this thread, l-sarosy.

@Fiat Lux - ASIA is right! To add up, I highly recommend contacting our QuickBooks Online Support Team so they can assist you with the master admin claim. 

The followings steps outlined below will guide you through:

1. Sign in to your QuickBooks Online company.
2. Select Help (?) at the top right.
3. Select Contact Us to connect with a live support agent.
   

Just a heads up, we have limited staffing and have reduced our support hours to 6 AM-6 PM PT Monday-Friday due to the  COVID-19 outbreak. We will resume normal hours as soon as possible.

You can refer to this page: Contact Support for more details on how to get in touch with our live support team.

Check out the Change your QuickBooks Online master admin user link in case you want to transfer who manages your books.

Let me know if you need additional information, and we're always here to help you out.

Thank you and take care!