SEPA payment file validation non-UTF-8 characters for ISABEL and Belgium Banks

In our Belgium operating unit, we have supplier names and addresses with Belgium-French characters, e.g ë, é, è, à etc. We are able to create the SEPA payment file (PAIN 001.001.03) however when we load the file through ISABEL (Belgium banking software), the file fails due to the existence of non UTF-8 characters (in the supplier names). I have reviewed AP: SEPA: Which Character Set is supported and validated in SEPA XML Output Format? (Doc ID 1307781.1)

and can see that Oracle do not provide a solution (or validation) for this issue. I'd like to know how others have got around this problem. At the moment it seems the only solution available to us is to modify all supplier names and addresses to remove any Belgium specific characters.