At first the issue looks almost academic, because such cross-border payments currently account for only 1% of all payments sent by banks within the euro zone. But on closer examination it becomes clear that this affects businesses as well as individuals. A small business wanting to refund a customer in another euro-zone country might find that the bank charges not only eat up the refund but cost the poor customer money on top. Consumers wanting to buy goods by mail order may be unable to pay by cheque because the seller will be unwilling to accept a payment that carries a levy of nearly 25%.
The high cost affects adversely not only the businesses but also the individuals. 高昂的成本对企业和个人都造成了不利的影响。
on top
in addition to something, especially something unpleasant 除 … 之外(还)
e.g.
1)We missed the train, and on top of that we had to wait for two hours for the next one.
我们误了火车,此外,我们得等两个钟点下班火车才来。
2)Hail came on top of a violent thunderstorm.
一阵凶猛的雷雨后,紧接着下起了冰雹