I had the same error and the issue was around my middle name.
Ensure that your first name, middle name, and last name details match how you provided them while applying for SIN.
Apparently while applying for the SIN, I had provided my middle name as a separate field.
While filing the tax return, I tried including the middle name in the first name field. Hence the error.
Getting error 31 when filing tax for 1st time, I verified all the SIN info
in NETFILE and filing
Posted
I had the same error and the issue was around my middle name.
Ensure that your first name, middle name, and last name details match how you provided them while applying for SIN.
Apparently while applying for the SIN, I had provided my middle name as a separate field.
While filing the tax return, I tried including the middle name in the first name field. Hence the error.