What's with the DTC supplementary under 18 amount?

Yet again, a client who claims the DTC transfer for their child under 18 misses claiming the DTC supplement.

This supplementary amount tops up the DTC (disability tax credit) both federally and provincially, but it's clawed back by any child care expense claims by anyone. The supplementary amount is mentioned under the Disability amount transferred from a dependent but CRA really don't explain it very well at all

http://www.cra-arc.gc.ca/E/pub/tg/rc4064/rc4064-e.html#P614_55944

well, what do you know, it's finally explained somewhere - the new Folio has two paragraphs that describe how to calculate it, but they only talk about the federal component, and there is a provincial/territorial component that of course will vary by the province/territory.  IF someone finds a chart that lists those amounts, please share it!!!!

http://www.cra-arc.gc.ca/tx/tchncl/ncmtx/fls/s1/f1/s1-f1-c2-eng.html#N1049A

"Supplemental amount

2.27 The supplemental amount is available to an eligible person with a disability who is under 18 years of age at the end of the tax year. The maximum supplemental amount is a fixed amount ($4,402 for 2012), that is indexed each year in accordance with subsection 117.1(1). In certain circumstances, discussed at ¶2.28 below, the supplemental amount may be reduced. Assuming there is no reduction to the supplemental amount for the tax year, the maximum tax credit available in respect of the supplemental amount for 2012 is $660 (15% x $4,402).
2.28 The supplemental amount may be reduced where an amount paid in the year for the care or supervision of the eligible person with a disability is claimed by any person as a child care expense deduction under section 63, a disability supports deduction under section 64 or a medical expense tax credit under section 118.2 for the tax year. The reduction in the supplemental amount is the amount by which the care or supervision costs so claimed exceed a fixed amount. The fixed amount for 2012 is $2,578 and is indexed each year in accordance with subsection 117.1(1). If the amount paid for care and supervision of the eligible person with a disability, and claimed under section 63, 64 or 118.2 is $6,980 (for 2012) or more, the supplemental amount is reduced to nil."

The tax software out there that people use to file their own taxes doesn't seem to capture this extra credit, and I don't know how many times it's one of the things I've found that gives people an extra amount of refund every year (and back 10 years).

It's one of the reasons I get called the "TaxDetective".  It's because amounts like this are hidden, and in fact, CRA is not very forthcoming about disclosing that this extra supplementary amount exists either. Some years it completely disappears from all of their website and printed materials. Then I / and other people like me complain, and it re-surfaces.

This supplementary DTC disappears at age 18. The whole credit system for claiming for an adult child with a disability is completely different. The child has to file a return to claim their own DTC first, and then, the parent or other supportive relative can transfer any amount not used by the person over 18 (there's a long list of who that can be) and they don't have to live with you to claim some credits.

I have a web page with information about the transition to adult as the Pacific Spirit transition group asked me to speak about this topic and it was so muddled that I put together this page to remind myself of what all the rules are and how many things change at or about the time your child with a disability transitions to adult for tax purposes.

http://www.taxdetective.ca/youth.html

Remember, many of the personal tax credits can be apportioned between supportive relatives, which means that if one person claims the credits, but can't use all of them, the remainder can be allocated to a second or third supportive person. It's also possible to agree on the allocation to split up the credits because everyone takes their turn...as long as no one takes more than their share, and if someone does, sometimes, everyone loses the right to claim. So take care and play safe.