CANADIAN DISABILITY TAX CREDIT CERTIFICATE (T2201)
If you have EHS, you may be eligible for a non-refundable tax credit used to reduce income tax payable on your tax return.if you qualify for the disability amount and you have working income, you may be eligible for a working income tax benefit disability supplement.
see http://www.cra-arc.gc.ca/witb/ for more details
Who is eligible for the disability amount?
You are eligible for the disability amount only if a qualified practitioner certifies, on the form, that you have a prolonged impairment, and certifies its effects, and the CRA approves the form.
It is improtant that your doctor fill in dates of when the symptoms started and not the date of diagnosis. If qualified, a taxpayer can request retroactive adjustments for up to 10 years of tax returns. To claim the adjustment on the previous tax returns filed, you would file the disability certificate and a T1-ADJ request for each year, with a covering letter.
You can send the form to the CRA at any time during the year. By sending your form before you file your tax return, you may prevent a delay in your assessment. They will review your application before they assess your return.
For the form and more details go to
http://www.cra-arc.gc.ca/E/pbg/tf/t2201/README.html
Formats available are: PDF, PDF fillable, E-text, Braille, and Large print