Electronic European VAT Reporting

For those companies that are doing Electronic European VAT Reporting, what medium are you using to send your files to HMRC? Medium as in who is your web services provider for calling the APIs provided by HMRC? Or by what means are you meeting the regulations for sending tax files?
Thanks.

@Kimberly Ulmer
Hi, we (Interface European Manufacturing )are going to use the add-on "SII extractor" + SERES as provider for Spanish VAT reporting. This is all provided via Quistor, JDE contultancy partner. We are still in the process of determining the approach/tool for UK VAT reproting.
Nienke van Elst

@Kimberly Ulmer I have the same question so following this!