Thanks for connecting with us. I've got some information on this.
I was able to confirm that there's an ongoing issue with entering a company phone number producing an error QuickBooks Online (QBO). As a workaround, enter the country code and a space before the phone number.
Standard UK format: +44 123456 7890
Workaround: +44 1234567890
So you'll be able to receive updates on this investigation, I suggest reaching out to our Phone Support Team. When you do, provide this escalation number: INV-25811.
Sign in to QBO.
Go to Help and click on Contact us.
Enter your concern and select Let's talk.
Choose either Chat or Geta callback.
From there, you should be able to enter the company phone number.
Keep me posted on how it goes by leaving a comment below. I'll be sure to get back to you.