26 CFR §301.6532-3

1. (a)General rule. No suit or proceeding, except as otherwise provided in section 6532(c)(2) and paragraph (b) of this section, under section 7426 and § 301.7426-1 relating to civil actions by persons other than taxpayers, shall be begun after the expiration of 9 months from the date of levy or agreement under section 6325(b)(3) giving rise to such action.
2. (b)Period when claim is filed. The 9-month period prescribed in section 6532(c)(1) and paragraph (a) of this section shall be extended to the shorter of,
   1. (1)12 months from the date of filing by a third party of a written request under § 301.6343-1(b)(2) for the return of property wrongfully levied upon, or
   2. (2)6 months from the date of mailing by registered or certified mail by the district director to the party claimant of a notice of disallowance of the part of the request to which the action relates. A request which, under § 301.6343-1(b)(3), is not considered adequate does not extend the 9-month period described in paragraph (a) of this section.
3. (c)Examples. The provisions of this section may be illustrated by the following examples: