The ATO has advised that it will begin implementing itsnew income tax processing system from today.This means that many ATO systems will be unavailable from 12.01am EDT Friday, 22 January to 6.00am EDT Wednesday, 27 January 2010.As a result there will be no access to information through the ATO's portals during this period. Also, ATO call centre staff will only be able to provide limited assistance as they will not have full access to personal or account information.For further details, visit the ATO website.