15 2/14 4 Settlement of balances of account 2/15 4.1 All international maritime telecommunication accounts shall be paid by the accounting authority without delay and in any case within six calendar months after dispatch of the account, except where the settlement of accounts is undertaken in accordance with 4.3 below. 2/16 4.2 If international maritime telecommunication accounts remain unpaid after six calendar months, the administration that has licensed the mobile station shall, on request, take steps, within the limits of applicable national law, to ensure settlement of the accounts from the licensee. 2/17 4.3 If the period between the date of dispatch and receipt exceeds one month, the receiving accounting authority should at once notify the originating service provider that queries and payments may be delayed. The delay shall, however, not exceed three calendar months in respect of payment, or five calendar months in respect of queries, both periods commencing from the date of receipt of the account. 2/18 4.4 The debtor accounting authority may refuse the settlement and adjustment of accounts presented more than twelve calendar months after the date of the traffic to which the accounts relate, unless provided otherwise under national law in which case the maximum deadline can be within eighteen calendar months.