Regulatory authorities globally have implemented systems to review submissions in eCTD format.  FDA CDER has required eCTD format since January 1, 2008.  The European Medicines Agency (formerly EMA) has required eCTD format for submissions using the centralised procedure since January 1, 2010.  FDA CBER is insisting on eCTD format for BLA submissions under priority review or using the rolling submission process.

What could possibly go wrong with your eCTD?

...Plenty!

Every regulatory authority receiving eCTD submissions performs a programmatic validation of compliance with the eCTD standards. If any aspect of your submission fails validation – your submission must be corrected and resubmitted. The review clock doesn’t start until you submit a valid eCTD.