If I must pay more than $3000 on filing for 2013, and in two previous years I got a refund, is there any penalty or new obligation to pay taxes by instalments?
It would be possible to shift medical, charitable, and pension splitting to my spouse to bring my amount payable under $3000, but we would pay about $300 more in tax. That would need to be compared with any consequences for having an amount larger than $3000 owing on this year's return.