Hi there, @NarjisACCA & @LincolnLoc,
We are currently experiencing an issue where QuickBooks Online customers are unable to access their companies. Our team is actively working to resolve this and return you to work as quickly as possible.
Check the QuickBooks status page to see its current updates. Select Subscribe to updates on the status page. We’ll send you a message when a service is down or scheduled for maintenance. We’ll also share the good news when it’s back up and running.
Thank you for your patience while we work for a fix. Keep in touch if you need any more assistance with this, or there's something else I can do for you. I've got your back. Have a good day.