Can attachments be filed to the Form 990 to provide additional information?
Generally, narrative responses to particular questions for which no space exists in the appropriate Part or schedule should be placed on Schedule O, Supplemental Information to Form 990. All Form 990 filers must provide responses to certain questions (e.g., Part VI, lines 11 and 19) on Schedule O, and may be required to include explanations of certain Yes and No responses in Schedule O. Some information that Schedule O cannot accommodate must be filed as attachments, as applicable. Examples include name change amendment to organizing document; articles of merger or dissolution, resolutions, and plans of liquidation or merger required for Schedule N; letters regarding termination of exempt status required for Schedule N; and list of subordinate organizations included in group return). Also, the IRS will accept software-prepared 2009 Forms 990 that refer to (and attach) statements or attachments that include narrative responses (or portions thereof) that do not fit in the software developers' allotted space for a particular question. Otherwise, if filers are unable to fit a narrative response to a particular question within the allotted space on the Form or schedule, they should include their response on Schedule O, not in a separate attachment.
Note that the reasonable cause explanation for late filing of Form 990 should not be in placed Schedule O, but in a separate attachment.