CFR › Title 26 › Part 301 › §301.6018-126 CFR §301.6018-1Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkFor provisions relating to requirement of estate tax returns, see §§ 20.6018-1 to 20.6018-4, inclusive, of this chapter (Estate Tax Regulations).