Not sure about all of it, but I believe you can claim the kid as spouse amount, or as kid amount, not both.
What are the situations in which you cannot claim the amount for an eligible dependant?
Even if all of the conditions have been met to claim the amount for an eligible dependant (read Can you claim the amount for an eligible dependant?), you cannot claim this amount if any of the following applies:
You or someone else is claiming a spouse or common-law partner amount (line 303) for this dependant.
I am also unsure about the Canada employment amount -- do you need qualified expenses to claim this one? A lot of normal expenses can not be claimed, like work clothes, though I think uniforms and computers that are required by your employer for you to supply are allowed. (if the expense was optional,ie., not a mandatory condition of employment, it is not usually allowed and employment expense)., Also this credit can not be claimed for self employment, as should be a business expense instead, not a tax credit...
Finally, don't forget that this the gross amount of the tax credits -- that nice old 15% applies to the total.
(or whatever formula works for that credit amount)
Generally, the total numerical value of tax credits is not one and the same as the amount of tax "credit" -- correct, these are usually very, very different, not only because of the tax brackets, but also because most people have far fewer credits. It is not common that one's credits equals one's income, without very high medical or donations as a % of income.
Income of $42881 would normally result in a tax of $6429.
But tax credits totalling $42881 reduce taxes due by $6429...
Other than the fact that you have missed the BC taxes portion (which brings the federal 15% to a combined 20.06% with a slightly different tax bracket cut off) you are correct.
As well, this means that you could make up to $42881 (actually minus the canada employement credit and kid amount, I think), and pay no tax.
Your govt monies (UCB, child bonus, etc) also start to decrease after you get to a certain amount.
WITB credit applies when your family income is under about $20k (more for larger families), and applies to employment income, which would raise the amount you could earn tax free.--- but your disability tax credits is greater than this, just good to know if you did not have them.
Net income level where the recipient is not eligible to receive the working income tax benefit (WITB)
2014 tax year
Single with children-- $28,316 (BC)
It declines from about $11k to the $28k, but is still valuable, if you have earned income.
Income includes UCB payments and other govt money... plus interest, dividend (at a preferred tax rate), withdrawls from RRSPs, etc.