Although I specialise in financial accounting and reporting, I'm afraid that I'm not aware of any reliable online accounting/financial reporting glossaries etc. for either English-German or German-English. Neither are there any usable dictionaries, for that matter.
One online resource that you may find useful is the text of the International Accounting Standards (IASs) adopted for use in the EU and published by the European Commission in all EU official languages. At the least, you should then be able to search e.g. the English PDFs for terms and match them with the German PDFs. Details of where to find these resources are in a posting to this Forum in October 2003.
Thank you, Robin.