If my last name is more than 20 characters how do I complete if the software is 20 characters allowed?

[MichaelMc]

Enter the first twenty characters. That information, plus your Social Security number, will be sufficient to allow the IRS to verify your identity and locate your income tax records.

Please understand that all TurboTax forms fully conform to IRS requirements to assure accurate processing. Any data specifications, such as field length, are provided to our product developers by the IRS.