QB Issue Resolution:
In the Invoice window templates pop up, choose Edit current template to open up Layout Designer. In Layout Designer, choose File->Delete Template.
Select the template you want to delete and press the delete button.
I don’t think you can delete the built in templates (they aren’t in your file – they are stored in the QuickBooks application).
Resolution for Issue 'Is there any way I can delete a invoice template in my quickbooks Mac 2014' available: Yes (Solved).
Source: Intuit Community forum.
Is there any way I can delete a invoice template in my quickbooks Mac 2014: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.Support for Invoice
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