48 CFR §25.1002

1. (a)Unless an international agreement or the WTO GPA (see 25.408(a)(4)) requires a specific currency, contracting officers must determine whether solicitations for contracts to be entered into and performed outside the United States will require submission of offers in U.S. currency or a specified foreign currency. In unusual circumstances, the contracting officer may permit submission of offers in other than a specified currency.
2. (b)To ensure a fair evaluation of offers, solicitations generally should require all offers to be priced in the same currency. However, if the solicitation permits submission of offers in other than a specified currency, the contracting officer must convert the offered prices to U.S. currency for evaluation purposes. The contracting officer must use the current market exchange rate from a commonly used source in effect as follows:
   1. (1)For acquisitions conducted using sealed bidding procedures, on the date of bid opening.
   2. (2)For acquisitions conducted using negotiation procedures—
      1. (i)On the date specified for receipt of offers, if award is based on initial offers; otherwise
      2. (ii)On the date specified for receipt of final proposal revisions.
3. (c)If a contract is priced in foreign currency, the agency must ensure that adequate funds are available to cover currency fluctuations to avoid a violation of the Anti-Deficiency Act (31 U.S.C. 1341, 1342, 1511-1519).