Canadian corp that gets US Canadian tax treaty exclusion for US income tax. Files 1120F and an 8833 tax treaty position disclosure. Looks like MASS actually has a form, Sched TTP for this. But I cannot figure out from the form or instructions how/where the exclusion flows from the TTP to the Mass Excise Tax form. (Mass could take days to respond to my email and won't answer tech questions like this over phone.)