Xero don't have a support phone number. What this means as a Xero user is that support requests will need to be done via ticket within Xero. What Xero do have is a call back request option on Xero Central. Here, you can let them know your preferred time to call and they'll get in touch. If you have a more immediate question you want help with in your accounts, you can always use our paid Xero support
You can get help from Xero from within your Xero organisation by clicking on the question mark (?) icon on the top right. This will link you through to Xero Central where you can click on 'Contact Xero Support' to raise a new ticket. Raising tickets in this way allows you to see when Xero support have been in contact with you and manage the cases.