H.R.1204: To amend the Internal Revenue Code of 1986 to impose penalties for the failure of 527 organizations to comply with disclosure requirements.

527 Transparency Act of 2007 - Amends the Internal Revenue Code to revise disclosure requirements for tax-exempt political organizations (527 organizations) to require monthly reporting of contributions and expenditures. Imposes a penalty tax on political organizations that fail to meet disclosure requirements. Denies a gift tax exclusion for donations to political organizations that fail to meet disclosure requirements.

Requires political organizations to file disclosure reports simultaneously with the Secretary of the Treasury and the Federal Election Commission (FEC).