I am going to assume filing as couple is filing as a couple irrelevant to gender in Canada. Hubby and I are a hetero couple so I have never had to look at/deal with taxes as a same sex couple so I don't know what has or has not changed in that respect. Neither hubby or I claim the other a dependent as we each make too much money ((according to the Canadian Gov't.... try living in Vancouver we wonder where our money goes lol)), the only stuff we claim that pertains to each other is we need to show the salary from our T4 of each on our claim and our joint investments (GICs/Joint account).
My question was more, is there an option to file a joint return? I've never come across it.
The legal definition of spouse (in Canada) is someone (yes, gender neutral) that you have cohabited with for 1 year or longer. In fact you can be sued for spousal support if one person supported the other for that year even if you didn't have any form of non-platonic relationship.
As for claiming as a dependent, a non-disabled adult needs to earn VERY little to qualify for that in Canada. Even when I was a full-time student I didn't qualify. I could transfer my education credits to my DW, but, it was worth more (long term) to hold onto them and use them myself when I was making money.
Tax laws change somewhat annually you may want to look into it.
Believe me, I read the whole book every year...I'm weird that way.
I know that when I lived in the US people used to talk about "marriage incentives" but I never really understood what they were talking about. My guess is that this is what C&GsMama is talking about. But, I don't think we have equivalents in Canada other than being able to make donations to a spouses RRSP and claim that on your own taxes...but, again you only need to legally qualify as spouses and marriage is irrelevant.
As for charitable receipts I believe they need to go to the name of the person on the receipt; if it's jointly you share it or I believe can choose who benefits more.
Actually, I know this one well. The line is very clear that either spouse can claim a receipt in either spouses' name. This is true for both charitable receipts and uncovered medical costs.
It's set up to encourage a higher degree of charitable donations because you get a lesser credit for the first $200 annually than for donations above that. So, allowing both names means that those who donate a lot get the larger benefit for most of their donations.