For ads with a fair market value between $100 and $999; and appearing within 21 days of an election. - Within 5 days of making the expenditure. 

For ads with fair market value of $1,000 or more and appearing within 21 days of an election - Within 24 hours of, or on the first working day after, the date the ad was first published, mailed, or otherwise presented to the public.

Note: For an advertisement that clearly identifies at least one candidate for state, local, or judicial office; appears within 60 days of an election in the candidate's jurisdiction; is distributed through radio, television, postal mailing, billboard, newspaper or periodical; and, either alone, or in combination with other communications by the sponsor identifying the same candidate has a fair market value of $5,000 or more. - Must be filed electonically within 24 hours of, or on the first working day after, the date the ad was first published, mailed, or otherwise presented to the public.

C7 Special Political Expenditures Reports - (PDF)
Any business, union, association, organization or other entity -- except a lobbyist employer that files an L-3 report or a political committee that files C-4 reports -- making independent expenditures during a calendar year that total over $700 supporting or opposing state office candidates or statewide ballot measures must file a C-7.
Date Due: The report is due by the last day of February of the year following the one in which the expenditures were incurred and is in addition to the C-6 filing requirements.