If before the expiration of time prescribed in sections 289A.38 to 289A.382 and 289A.40 for the assessment of tax or the filing of a claim for refund, both the commissioner and the taxpayer have consented in writing to the assessment or filing of a claim for refund after that time, the tax may be assessed or the claim for refund filed at any time before the expiration of the agreed-upon period. The period may be extended by later agreements in writing before the expiration of the period previously agreed upon. The taxpayer and the commissioner may also agree to extend the period for collection of the tax.
When a taxpayer consents to an extension of time for the assessment of federal withholding or income taxes, the period in which the commissioner may recompute the tax is also extended, notwithstanding any period of limitations to the contrary, as follows:
Minn. Stat. § 289A.42
1990 c 480 art 1 s 22; 1991 c 291 art 6 s 14; art 16 s 9; 1998 c 300 art 1 s 4; 2005 c 151 art 2 s 9; 2006 c 212 art 3 s 25; 2007 c 13 art 3 s 16