File with an .XLTM extension contains a template of a spreadsheet document with the macros function active, in a format based on Open XML. The template may consist of arrangements, default settings or properties of the document. Unlike the XLTL templates, the XLTM files enable support for macros in created on their basis .XLSM spreadsheets.

Microsoft Excel, since the 2007 version for Windows and 2008 for Mac OS, enables to create templates stored in the same format. They can be opened also in earlier versions of Office Suite, provided they have a proper add-on installed that enables support for files in formats compliant with Open XML.