Excerpt:

INCOME TAX
Rev. Rul. 2007–51, page 573.
Limitations on setoff under sections 6402 and 6411.
This ruling holds that the Service may credit an overpayment
against unassessed internal revenue tax liabilities that have
been determined in a statutory notice of deficiency sent to
the taxpayer. It further holds that under section 6411(b) of
the Code, the Service may credit a decrease in tax resulting
from a tentative carryback adjustment against unassessed
liabilities determined in a statutory notice of deficiency.
Rev. Rul. 54–378 clarified.
Rev. Rul. 2007–52, page 575.
Definition of a liability under section 6402(a) and
6411(b). This ruling holds that the Service has the right
under section 6402 of the Code to credit an overpayment
against internal revenue liabilities for which no assessment has
been made, or statutory notice of deficiency issued, when the
liabilities are identified in a proof of claim filing in a bankruptcy
case. Similarly, the ruling holds that the Service has the right
under section 6411(b) to credit a decrease in tax resulting
from a tentative carryback adjustment against internal revenue
tax liabilities for which no assessment has been made, or
statutory notice of deficiency issued, when the liabilities are
identified in a proof of claim filed in a bankruptcy case.
Rev. Rul. 2007–53, page 577.
Revocation of Rev. Rul.; tentative allowance. The IRS
has determined that Rev. Rul. 78–369 is inconsistent with the
regulations under section 6411 of the Code. Rev. Rul. 78–369
revoked.

Notes:

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