Earnings for CPP/QPP additional contributions (field 373)

Program(s) affected: T1 Document created: 02 11, 2014 Tax year(s): 2013 Document last modified: Version(s): 17.10, 17.11 Problem status: Fixed in v17.13

Should I file the tax return of a taxpayer who is not a resident of Quebec and is electing to pay additional CPP/QPP contributions?

No, you should wait for a subsequent release of DT Max. As per a recent revision from CRA:

Where the client is not a resident of Quebec and is electing to pay additional CPP/QPP contributions, enter the amount of the CPT20 election on "other than T4 income" (if any), plus, for processing purposes, the amount of the CPT20 election on "T4 income" (if any), at field 373.

The current version of the program does not reflect this change.