Hi Roberto

You can check Knowledge base article  41370 for import orders 

Furthermore, you can try go to vendor record, import/export tab, enable "this customer uses my item numbers on orders",  enable, in this case, when you email an order, it creates an import .imp sample format file

You can go to Sage 50 , help, search,  "create a vendor record" under stub title  "This vendor uses Sage 50 Accounting, and I want to be able to import and export transactions with them" for detail info

Roberto, I'm not sure if you are aware of this, but an .imp file is actually a .csv file with a specific format. If you can create a .csv file, then you can create an .imp file -- both are text files in the strictest sense and both can be edited with any text editor.

I just exported roughly 500 invoices from Quickbooks to bring them into Sage 50. I exported from quickbooks into a spreadsheet and then did some processing of the spreadsheet to generate an .imp file (which. as I said, is really just a .csv file with particular headers)

Do you have an example of the file you used?  

Jason's post explains how to generate a .IMP file that should work as an example. 

Because it's generated by your system, it will have your tax codes in the detail, the right version and country codes in the header, etc.