California will accept a third quarter payment, so that's why there's a voucher. I agree, it's confusing, since they slate the estimates as not wanting one. But I think it's a grace move to the OCD people who want to divide annual estimates by four and send in even amounts.
It's also idiot insurance, because about once every 2-3 years, I still get one panicked email or call about not having a payment amount for Q3 for CA. I typically suppress the vouchers to try and get my clients to e-pay, but maybe I should let them through...hmmm...
