A certain amount of folklore has developed around the income tax system and the filing of tax returns, but some of those age-old perceptions may not be accurate — at least, not any more.

Here are 10 tax-filing myths and the facts that could save you a lot of money:

Myth 1: I don't need to file a tax return, because I don't earn enough money to pay income tax.

Unfortunately, many Canadians believe this and therefore miss out on potentially thousands of dollars in benefits and credits like the GST/HST credit and the Canada Child Tax Credit. People need to file a return to be eligible.

Low-income seniors who qualify for the Guaranteed Income Supplement should also file to ensure that they continue to get the supplement. Otherwise, they'll have to file a separate renewal application.

In the same vein, low-income earners who got Working Income Tax Benefit payments last year have to file a 2010 return to be eligible to receive them in 2011.

Some provinces also provide tax credits like sales tax credits or property tax credits for low income earners. But again, no return, no credit.

Teenagers who earned a few thousand dollars doing odd jobs should also file a return because that creates RRSP contribution room (even if they didn't contribute to an RRSP). That unused contribution room can be carried forward indefinitely to use when they will owe tax.

Myth 2: If you don't have the money to pay your tax bill, there's no point in filing before the Apr. 30 deadline.

If you can't come up with the taxes owing by Apr. 30, file on time anyway and pay later. The Canada Revenue Agency imposes a five per cent penalty for late filing, not for paying late. "Interest will accrue on the unpaid balance, but the penalty will not apply," advises KPMG.

Myth 3. It's too late to change your tax return once the Canada Revenue Agency has processed it and sent you your Notice of Assessment.

People often come across new income slips or donation receipts after they file. The CRA says nothing new should be sent until you get your Notice of Assessment. Then you should file a T1 Adjustment Request form.

H&R Block advises that if it's an income slip like a T4, T4A, or T5 you should request an adjustment right away. "The longer you wait, the more interest you'll be charged," the tax preparation company says. "Should the CRA discover unreported income twice within a four-year period, you will be subject to an automatic penalty." And what if you find a charitable donation slip form five years ago or find something else that would have given you more money back? You can still ask for that adjustment. If you have the paperwork to back up your claim, the CRA's policies allow taxpayers to go back up to 10 years to request an adjustment.

Myth 4: I needn't bother to claim any tuition-related tax credits, because I didn't make enough money to owe any tax.

If students don't need to use the tuition tax credit, the education amount or the textbook tax credit because they have no tax to pay, they can transfer those credits to their spouse, common law partner, or even a parent or grandparent. They can also carry forward any tuition, education or textbook credit they didn't use or transfer to any future year when they will have tax to pay.

Myth 5: I can file my tax return through the internet, but it's impossible to pay electronically.

That used to be the case, but paying by electronic banking is easy these days. As of the 2009 tax year, taxpayers will also be able to remit amounts owing to the CRA through the department's new My Payment feature .

Myth 6: I can't file my tax return until a missing T-4 slip turns up.

You should have received all of your employment-related income slips by the end of February. If you never got a slip (or the dog ate it) you should contact whoever issued it and ask for a duplicate. If that doesn't work, don't wait so long that you pay the five per cent late filing penalty that kicks in after Apr. 30.

Estimate how much you think you made and attach a note to your return saying you weren't able to get your slip. And provide the name and address of who should have given you that slip.

Myth 7: I never got my tax refund because I moved five years ago and didn't leave a forwarding address. I guess I'm just out of luck.

You wouldn't think there would be unclaimed tax refunds kicking around. After all, the cheques go out just a few weeks after people file their taxes. But there are. As of the end of 2007, there were 38,551 undeliverable and unclaimed refund cheques worth $25,372,066 just waiting to be cashed by taxpayers who paid too much tax.

The Canada Revenue Agency says it goes to great lengths to try to track down these people. It scours phone books, surfs the web, and even checks with neighbours. Often, however, people move and forget to notify anyone, including the tax department. Sometimes they leave Canada to return to the "old country" and forget to notify the tax department. And sometimes, they just die (and so can be forgiven for forgetting to notify the tax department).

There's no web-based search engine, though. Privacy laws forbid that. So if you think you've got a refund coming but never got it, contact your local office of the Canada Revenue Agency for details on how to make a claim.

No interest is paid on unclaimed refunds, but there's no charge for the service, and there's no time limit on making a claim.

And it's not just income tax refund cheques that we're talking about here. The tax department also has unclaimed GST Credit cheques and Canada Child Tax Benefit cheques.

Note: The above is taken from CBC.ca's Guide to finding lost money series.

Myth 8: I deliberately didn't declare a lot of income a few years ago, and it's bothering me, but if I come forward now, I'll risk a serious fine or jail time.

The Canada Revenue Agency has a Voluntary Disclosures Program that thousands of people with guilty consciences apply to take advantage of each year. The CRA says 11,393 applied in the 2008-2009 tax year. Almost 8,000 disclosures were accepted, but 1,506 were rejected for not qualifying as "valid" disclosures and the rest were withdrawn by taxpayers.

People who haven't filed a return for years or those who "forget" to declare income can come clean and not be liable for penalties or prosecution (although they will have to pay interest and the taxes owed).

There are a few crucial conditions. For one thing, the disclosure must be complete. For another, it must be made before the tax department starts snooping into your affairs. Once you know they're on to you, it's too late to 'fess up.

The program allows for "no name" disclosures through an authorized representative.

Myth 9: The tax department doesn't care if personal circumstances make it difficult or impossible to pay my taxes.

Couldn't file on time because of a serious illness or your house caught fire? The CRA is willing to let you file late without imposing penalties. In 2008-2009, more than 63,000 taxpayers filed for cancellations and waivers of penalties and interest under the CRA's taxpayer relief provisions.

The CRA also says it can forgive interest when taxpayers have lost their job and can't pay what they owe. Read more about the CRA's taxpayer relief provisions here.

Myth 10: You can often make a deal with the CRA to pay less tax than you owe.

People may wish that you could negotiate to pay, say, 60 per cent of your tax bill and call it a day, but the CRA says it generally doesn't do this.

Here's how the CRA put it in an email to CBC News:

"While the CRA has a certain amount of leeway to help taxpayers who find themselves in particularly difficult circumstances, Canadian legislation allows for forgiveness of actual tax debts only in very precise and limited situations, and only as specified by law."

So what are those situations? The CRA says they include:

Remission under subsection 23(2) of the Financial Administration Act.

A proposal made under section 50 or 66.12 of the Bankruptcy and Insolvency Act.

A reorganization plan made under sections 4 and 5 of the Companies' Creditors Arrangement Act.

A recovery plan made under paragraph 5(1)(a) or (b) of the Farm Debt Mediation Act.

The bottom line is that you won't get a break unless you're facing extreme financial hardship and are on your way to bankruptcy or something close.

If you aren't, the CRA says you'll have to pay every cent of the principal you owe. The agency makes no apology for this. The tax department points out that most Canadians do pay everything they're supposed to.