I've been using Ufile for years but always the installed version, now using the online version for the first time. I've also been entering our taxes the same way.
Box 14 on the T5007 is only used for Manitoba taxpayers. It has two valid values 0 if the taxpayer receives EIA (employment income assistance) or 1 if the taxpayer receives any other sort of social assistance.
You should be able to put a 0 in that field but when I try it for my son's return I get the following error:
You entered a percentage of less than 1% for box 14 of the T5007 slip. Since UFile will be using 0%, the Manitoba credits (MB479) will not be claimed.
It seems that the program thinks this value is a percentage rather than a way to just categorize the type of social assistance.
I'm pretty sure this is a bug as I checked last year's file and I entered a 0 in there and was able to e-file a year ago.
