Applying different general terms and Conditions

Dexxter does not offer a solution for this. What I do is the next:

I create my invoices in MS Word and export them to pDF. I have 1 document with general terms and Conditions (also in pDF) and 2 separate special terms and Conditions (depending on which terms and Conditions apply to which services). I then merge 3 pDFs (invoices, terms and Conditions, and the applicable special terms and Conditions). You can do this free with an app such as https://www.ilovepdf.com/merge_pdf. I then sign the document digitally with itsme and upload it to Dexxter. I do the same with quotations, by the way.