Sage 50 has a built in import utility, that basically takes a CSV formatted header plus the data, and can dump it into an invoice.

If you want to see the format, one easy way is to open the sample test file, set up a customer as using Sage 50 and having the same item numbers as you, create an invoice in that customer, and email it to yourself.  The .IMP file will show you the format.

The import format for a Sales Invoice is also documented in the SDK.

If you want the SDK documentation, or to use .NET, you can download the latest SDK here:

http://na.sage.com/sage-50-accounting-ca/lp/partners/sdk/

There is sample code in the sample project, in the C# folder that creates an invoice. (among other things)

I hope that helps, please post back.

Microsoft c# tutorials:
http://msdn.microsoft.com/en-us/library/aa288436(v=vs.71).aspx

Sage 50 has a built in import utility, that basically takes a CSV formatted header plus the data, and can dump it into an invoice.

If you want to see the format, one easy way is to open the sample test file, set up a customer as using Sage 50 and having the same item numbers as you, create an invoice in that customer, and email it to yourself.  The .IMP file will show you the format.

The import format for a Sales Invoice is also documented in the SDK.

If you want the SDK documentation, or to use .NET, you can download the latest SDK here:

http://na.sage.com/sage-50-accounting-ca/lp/partners/sdk/

There is sample code in the sample project, in the C# folder that creates an invoice. (among other things)

I hope that helps, please post back.

Microsoft c# tutorials:
http://msdn.microsoft.com/en-us/library/aa288436(v=vs.71).aspx