is the rate in force, as published in the C series of the  Official Journal of the European Union,  on the  first day of the month in which the payment period ends.  Suspension of the payment period as provided for in Article II.21.7 is not considered as giving rise to  late payment. Interest on late payment covers the period running from the day following the due date for payment  up to and including the date of payment as defined in Article II.21.1.  However, when the calculated interest is EUR 200 or less, it must be paid to the contractor (or leader  in the case of a joint tender) only if it requests it within two months of receiving late payment.  II.22 REIMBURSEMENTS  II.22.1 If provided for in the special conditions or in the tender specifications, the contracting  authority must reimburse expenses directly connected with the provision of the services either  when the contractor provides it with supporting documents or on the basis of flat rates.  II.22.2  The contracting authority reimburses travel and subsistence expenses on the basis of the  shortest itinerary and the minimum number of nights necessary for overnight stay at the  destination.  II.22.3  The contracting authority reimburses travel expenses as follows:  (a) travel by air: up to the maximum cost of an economy class ticket at the time of the  reservation;  (b) travel by boat or rail: up to the maximum cost of a first-class ticket;  (c) travel by car: at the rate of one first class rail ticket for the same journey and on the  same day;  In addition, the contracting authority reimburses travel outside Union territory if it has given its prior  written approval for the expenses.  II.22.4  The contracting authority reimburses subsistence expenses on the basis of a daily subsistence  allowance as follows:  (a) for journeys of less than 200 km for a return trip, no subsistence allowance is payable;  (b) the daily subsistence allowance is payable only on receipt of supporting documents  proving that the person concerned was present at the destination;  (c) the daily subsistence allowance takes the form of a flat-rate payment to cover all  subsistence expenses, including meals, local transport including transport to and from the  airport or station, insurance and sundries;  (d) the daily subsistence allowance is reimbursed at the flat rates specified in Article I.4.3;  (e) accommodation is reimbursed on receipt of supporting documents proving the necessary  overnight stay at the destination, up to the flat-rate ceilings specified in Article I.4.3. II.22.5  The contracting authority reimburses the cost of shipment of equipment or unaccompanied  luggage if it has given prior written approval for the expense.  II.23 RECOVERY  II.23.1  If an amount is to be recovered under the terms of the contract, the contractor must  repay the contracting authority the amount in question.  33 