11 1/10 2 Establishment of accounts 1/11 2.1 Unless otherwise agreed, the authorized operating agencies responsible for collecting the charges shall establish a monthly account showing all the amounts due, and send it to the authorized operating agencies concerned. 1/12 2.2 The accounts should be sent as promptly as possible, taking into account relevant ITU-T Recommendations, and, except in cases of force majeure, before the end of a period of 50 days following the month to which they relate, unless otherwise mutually agreed. 1/13 2.3 In principle, an account shall be considered as accepted without the need for specific notification of acceptance to the authorized operating agency which sent it. 1/14 2.4 However, any authorized operating agency has the right to question the contents of an account within a period of two calendar months after the receipt of the account, but only to the extent necessary to bring any differences within mutually agreed limits. 1/15 2.5 In relations where there are no special agreements, a quarterly settlement statement showing the balances of the monthly accounts for the period to which it relates shall be prepared and issued as soon as possible by the creditor authorized operating agency, and shall be sent to the debtor authorized operating agency, which, after verification, shall return a copy endorsed with its acceptance. 1/16 2.6 In indirect relations where a transit authorized operating agency acts as an accounting intermediary between two terminal points, Member States shall endeavour to ensure that authorized operating agencies include accounting data for transit traffic in the relevant outgoing traffic account to authorized operating agencies beyond it in the routing sequence as soon as possible after receiving the data from the originating authorized operating agency, in accordance with the relevant ITU-T Recommendations. 1/17 3 Settlement of balances of accounts 1/18 3.1 Choice of the currency of payment 1/19 3.1.1 The payment of balances of international telecommunication accounts shall be made in the currency selected by the creditor, after consultation with the debtor. In the event of disagreement, the choice of the creditor shall prevail in all cases, subject to the provisions in 3.1.2 below. If the creditor does not specify a currency, the choice shall rest with the debtor. 1/20 3.1.2 If a creditor selects a currency with a value fixed unilaterally or a currency the equivalent value of which is to be determined by its relationship to a currency with a value also fixed unilaterally, the use of the selected currency must be acceptable to the debtor. 1/20A 3.1.3 Provided the periods of payment are observed, authorized operating agencies have a right, by mutual agreement, to settle their balances of various kinds by offsetting: a) credits and debits in their relations with other authorized operating agencies; b) any other mutually agreed settlements, if appropriate.