The following is from https://www.acquisition.gov/far/html/Subpart%2013_2.html
And here is the "word", but much of the bold is from me:
Subpart 13.2—Actions At or Below the Micro-Purchase Threshold
(a) Agency heads are encouraged to delegate micro-purchase authority (see 1.603-3 see below).
(b) The Governmentwide commercial purchase card shall be the preferred method to purchase and to pay for micro-purchases (see 2.101).
(c) Purchases at or below the micro-purchase threshold may be conducted using any of the methods described in Subpart 13.3 (see below), provided the purchaser is authorized and trained, pursuant to agency procedures, to use those methods.
(d) Micro-purchases do not require provisions or clauses, except as provided at 4.1105 and 32.1110. This paragraph takes precedence over any other FAR requirement to the contrary, but does not prohibit the use of any clause.
(e) The requirements in Part 8 (see below) apply to purchases at or below the micro-purchase threshold.
(f) The procurement requirements in Subparts 23.2, 23.4, and 23.7 apply to purchases at or below the micro-purchase threshold.
(g)(1) For acquisitions of supplies or services that, as determined by the head of the agency, are to be used to support a contingency operation or to facilitate defense against or recovery from nuclear, biological, chemical, or radiological attack, the micro-purchase threshold is —
(i) $15,000 in the case of any contract to be awarded and performed, or purchase to be made, inside the United States; and
(ii) $25,000 in the case of any contract to be awarded and performed, or purchase to be made, outside the United States.
(2) Purchases using this authority must have a clear and direct relationship to the support of a contingency operation or the defense against or recovery from nuclear, biological, chemical, or radiological attack.
13.202 Purchase guidelines.
(a) Solicitation, evaluation of quotations, and award.
(1) To the extent practicable, micro-purchases shall be distributed equitably among qualified suppliers.
(2) Micro-purchases may be awarded without soliciting competitive quotations if the contracting officer or individual appointed in accordance with 1.603-3(b) considers the price to be reasonable.
(3) The administrative cost of verifying the reasonableness of the price for purchases may more than offset potential savings from detecting instances of overpricing. Therefore, action to verify price reasonableness need only be taken if—
(i) The contracting officer or individual appointed in accordance with 1.603-3(b) suspects or has information to indicate that the price may not be reasonable (e.g., comparison to the previous price paid or personal knowledge of the supply or service); or
(ii) Purchasing a supply or service for which no comparable pricing information is readily available (e.g., a supply or service that is not the same as, or is not similar to, other supplies or services that have recently been purchased on a competitive basis).
(b) Documentation. If competitive quotations were solicited and award was made to other than the low quoter, documentation to support the purchase may be limited to identification of the solicited concerns and an explanation for the award decision.
b) Agency heads are encouraged to delegate micro-purchase authority to individuals who are employees of an executive agency or members of the Armed Forces of the United States who will be using the supplies or services being purchased. Individuals delegated this authority are not required to be appointed on an SF 1402, but shall be appointed in writing in accordance with agency procedures.
Subpart 13.3—Simplified Acquisition Methods
13.301 Governmentwide commercial purchase card.
(a) The Governmentwide commercial purchase card is authorized for use in making and/or paying for purchases of supplies, services, or construction. The Governmentwide commercial purchase card may be used by contracting officers and other individuals designated in accordance with 1.603-3. The card may be used only for purchases that are otherwise authorized by law or regulation.
(b) Agencies using the Governmentwide commercial purchase card shall establish procedures for use and control of the card that comply with the Treasury Financial Manual for Guidance of Departments and Agencies (TFM 4-4500) and that are consistent with the terms and conditions of the current GSA credit card contract. Agency procedures should not limit the use of the Governmentwide commercial purchase card to micro-purchases. Agency procedures should encourage use of the card in greater dollar amounts by contracting officers to place orders and to pay for purchases against contracts established under Part 8 procedures, when authorized; and to place orders and/or make payment under other contractual instruments, when agreed to by the contractor. See 32.1110(d) for instructions for use of the appropriate clause when payment under a written contract will be made through use of the card.
(c) The Governmentwide commercial purchase card may be used to—
(1) Make micro-purchases;
(2) Place a task or delivery order (if authorized in the basic contract, basic ordering agreement, or blanket purchase agreement); or
(3) Make payments, when the contractor agrees to accept payment by the card.