As an advertiser, you can verify your transactions in menu 'Transactions' / 'Manage transactions'.
In this menu, you find all the transactions that have been generated in you affiliate program. Verify these transactions with the transactions in your own back office, and approve or disapprove them.
As advertiser you are obbliged to verifiy your transactions within two moths. It is important that you verify your transactions as soon as possible. Publisher find this very important. The sooner you veriefy the transactions, the more they will promote your program.
If you disapprove a transaction you should always give an explenation why the transaction is not valid.
In the menu, on the right, you find several options to help you verifiening transactions quicker. If you want to validad all your transactions in one time, read here the item about batch processing.