I've researched it at the OR Dept of Rev.....but have a wee bit of uncertainty.

CAN you base the current year estimates on 100/110% of the prior year?

The scenario is that I have a client with zero prior year Oregon liability (non- resident return) yet for 2018 his liability will be very large due to a $ 1.3 million capital gain.  

My uncertainty arises because CA has this little *gotcha* whereby, if the income is over $ 1 million, you can't use the prior year as a safe harbor.  

I just need a little hand-holding to make sure Oregon doesn't have the same gotcha & I haven't found it yet.  (I have a bad cold...and my head hurts...and I can't think clearly....)

TIA - I'm hoping one of you knows off the top o' your head; don't do any research