We strive to keep Clerk Invoices as simple as possible. We believe, that duplicating invoices instead of using templates should work for cases when you need to create similar invoices from month to month.
If you have a different scenario in your company and need invoice templates, please tell us about your case, and we will think of how we can cover your scenario in next versions of Clerk Invoices!
If You Still Need Invoice Templates in Current Version
You can use a simple workaround to have templates even in the current version of Clerk Invoices.
Just create all your templates as separate invoices with the Draft status and put them in January 2019. That month will be a storage for all your invoice templates. When you need to create a new invoice from a template, just go to January 2019, open the specific invoice template and click Actions ▸ Duplicate. That will create a copy of the template as a new invoice.