Okla. Stat. tit. 70, § 70-5-188: Supplemental appropriation of unencumbered balance –

Underestimations – Reapportionment to appropriation accounts.

Provided all fund balances reserved for unencumbered balance of

appropriations for the prior fiscal year on hand at the close of day

set by the board of education in the current fiscal year, but in no

event later than September 30, may be appropriated by supplemental

appropriation to current expense purposes in the current fiscal year

in the manner now provided by law. In the event of the recording of

an estimated encumbrance or in the event of an increase in the cost

of supplies, equipment, material, or services, these

underestimations may be provided for during the time period set by

the board by the cancellation of appropriations made by the county

excise board prior to June 30, subject to the approval of both the

governing board and the officer in charge of the department or

appropriation account only in instances as set forth and only in

amounts sufficient to pay the increased encumbrances, and by

reapportionment to the appropriation accounts in which an

underestimated encumbrance was made, all in the manner as now

provided by law for the making of supplemental appropriations.