I posted the question about attaching pdf files to a return and found that there is no current way to do it, despite the fact that my Turbo Tax Business program instructed me to do just that in order to submit my return. I've just spent hours on the phone with support and basically have learned that in the recent releases of Turbo Tax Business the 'attach file' operation is broken. I am now hoping that they can fix this in the next week or so.
This link (https://ttlc.intuit.com/replies/7348951) does not work. I need to attach a PDF file to a CO state return in order to be able to efile and not have the submission rejected. How would I go about attaching this DR1317 form to the return I would like to efile?
You should still be able to e-file your return but you will have to send the Form 1317 separately per these instructions: https://www.colorado.gov/pacific/sites/default/files/Income35.pdf