The IRS has several prior-year forms available for viewing and download on their website. While these forms will not be available for e-file without the prior-year software, they may prove useful for preparers to compare with current years.
Available forms include:
Form 1040 (2017)
Form 1040 (2016)
Form 941 (2017)
From 940 (2017)
Publication 15 (2017)
Form 1099-Misc (2017)
Form 1099-G (2017)
Be sure to visit https://www.irs.gov/forms-pubs/prior-year for more information.