The contact number is already linked to another contact. This can occur due to multiple reasons;

1. The contact was not exported, instead, the invoice was exported first creating a contact.
2. The linked contact in Xero has been archived
3. An Organisation has no Payer or Employer assigned, this can cause the first invoice exported to assume they are the Payer for that Organisation even if they’re a Student.

If the contact is not archived and a Payer has been assigned to the Organisation refer to the steps below.

1. Using Xero Contacts, Unlink the organisation and/or contact (Skip this step if already unlinked)
2. Using Xero Contacts, tick the box "Enable contact revisions" and search
3. Select the action "New Revision" of the organisation/contact
4. Then using the Import tool, search for the Xero contact & select the matching contact/organisation in the Action dropdown.

No duplicate contacts should be created on either platform.

Contact Validation Error when importing a contact.

This means that the contact in Xero doesn't currently have either a First or Last name. Xero contacts with no names can only be imported as Organisations.

Invoice or CN not of valid status for modification

The invoice or CN in Xero isn’t editable. Likely the invoice or CN has been voided or paid in Xero.
Review the status of the invoice or CN in Xero.

The account code or ID must be specified

One or more of the invoice or CN line items has no finance code assigned. Finance codes must be imported from Xero.

Account code ‘XXXX’ is not a valid code for this document

The invoice line item has a finance code that is not recognised by Xero. Create the finance code in Xero and/or import the finance code from Xero.

Item Code is invalid.

Xero Inventory is currently enabled, to resolve this either disable Xero Inventory or add the item code in Xero.

Item codes in aXcelerate are all automated and determined by the line item’s point of origin (Qualification Code, UoC Code, Workshop Type Code, or InHouseInvoices).

Payments & Refunds can only be made against Authorised documents

The invoice/CN has an outstanding amount lower than the payment/refund amount to 3 decimal places.

Importing Payments from Xero is marked as Invalid.

Ensure the linked contact in Xero has not been archived, if the contact is not archived refer to the steps below.

This is due to the contacts being incorrectly linked and usually only relating to organisations. The following process of creating a revision should resolve this issue.

1. Using Xero Contacts, Unlink the organisation/contact (Skip this step if already unlinked)
2. Using Xero Contacts, tick the box "Enable contact revisions" and search
3. Select the action "New Revision" of the organisation/contact
4. Then using the Import tool, search for the Xero contact & select the matching contact/organisation in the Action dropdown.

403 Forbidden & 429 Too many requests.

The Xero API limitation per minute has been met, please wait and try again.

1. Minute Limit: 60 calls in a rolling 60 second window
2. Daily Limit: 5000 calls in a rolling 24 hour window