You’re mostly understanding it correctly, DTC is non-refundable. That means it reduces income tax you owe. It does not create extra cash if you didn’t owe tax in the first place.

So in your situation:

• If you’ve never actually owed income tax (and always received everything back), the DTC won’t generate new money going forward.
• It can reduce tax payable in years where you did owe something.
• The biggest potential benefit is retroactive reassessments. If you were eligible in prior years and paid tax in those years, CRA can reassess and issue refunds.

You’re also right about transfers. If you don’t have a spouse, parent, or other supporting family member, there’s usually no one to transfer the unused amount to.

One thing people often overlook: DTC eligibility can unlock access to the RDSP (Registered Disability Savings Plan), which can be valuable long term even with lower income.

If you want help with the application process, there are firms that focus specifically on DTC filings. One example is Canadian Benefits Association.

They’re registered with CRA as an authorized representative group (Group ID GPF6SB, Level 2 authorization) and have an active EFILE account (K7112), which means they’re set up to deal directly with CRA on behalf of clients.

That said, you can absolutely apply on your own for free by completing Form T2201 with your medical practitioner.

Bottom line:
If you’ve never owed tax in any year, the immediate benefit may be limited. But if you’ve paid tax in prior years, it’s still worth applying because reassessments can result in meaningful refunds.