W.S. § 39-15-110 — Statute of limitations

(a) No credit or refund shall be allowed after three (3)
years from the date of overpayment. The receipt of a claim for a
refund by the department shall toll the statute of limitations.
(b) The department may bring an action to recover any
delinquent taxes, penalty or interest in any appropriate court
within three (3) years following the delinquency. In the case of
an assessment created by an audit, the delinquency period is
deemed to start thirty (30) days after the date the assessment
letter is sent. Any tax penalty and interest related to the
audit assessment shall be calculated from the filing period
during which the deficiency occurred. In any such action a
certificate by the department is prima facie evidence of the
amount due.
(c) Every vendor and person storing, using or consuming
tangible personal property in this state shall preserve within
this state for three (3) years suitable records and books as may
be necessary to determine the amount of tax for which the vendor
or person is liable under the provisions of this article,
together with invoices and books showing all merchandise
purchased. All records, books and invoices shall be available
for examination by the department during regular business hours
except as arranged by mutual consent.