Use of the euro
Article 13
The method chosen to convert expenditure incurred in a currency other than the euro into euro as set out in the programme, may be changed retroactively as of the start date of a programme implementation disruption, using the monthly accounting exchange rate of the Commission of one of the following months: (a) the month during which the expenditure was incurred; (b) the month during which the expenditure was submitted for examination by an auditor or by a competent public officer; (c) the month during which the expenditure was reported to the lead beneficiary.