Please do not take this the wrong way, but why in the world would you want to file an amended return so you could set up electronic estimated tax payments? Correct me if I'm wrong , but does not a tax preparer need a valid reason to file an amended return? What would you state to the IRS on the amended 1040 form  was your reason for filing a corrected return ? You stated yourself the client does not have to pay estimates , if they are so adamant about paying estimates why don't you just print them out and give them to the client and have them mail in the 1040 ES forms... come on man ... just my opinion