Riverview Ron

When I try to e-file Form 4868 for a partially completed tax return, I get an error message saying locked amount must be checked. The client is not making a payment as the return is not complete and the amount with the extension is incorrect. ATX will only allow one box to be checked so I cannot have all zeros on the 4868 and Lock Amount checked at the same time. How do I e-file the 4868?