Deadlines for paper or otherwise unstructured invoices (e-mail) to the public sector have been issued in many countries - and more are on their way. The reasons for this are obvious:
1. save tax payers money
2. move increasingly scarce human resources from administration to services and other productive tasks
3. kick-start e-invoicing in the economy at large and thus:
3.1. improve enterprise competiveness
3.2. fight the black and grey economy
3.3. collect VAT due - efficiently
3.4. establish innovation platform for the real time economy
The list of countries now having done this (in to-the-best-of-my-knowledge cronological order include: Denmark, Singapore, Italy, Spain, Sweden, Finland, Brazil, Greece, Mexico, Norway
Countries with partial deadlines and preparatory deadline-discussions include: Argentina (mandatory for importers in 2010), Portugal (may actually belong to the having-done-cathegory), USA (heading for 2012), Canada, Luxembourg, Russia.. The Netherlands
have issued an ambition to reach 80% in 4 years and the German Procurement Office (Bundesbeschaffungsamt) has electronified its process completely.
So where is your country? I am sure there are more good news around.