Mailed return April 5th, had money in my account on May 2nd.

You can. Any time up to four years after they mail the notice of assessment. E.g. if you filed your 2010 taxes on time and they mailed their notice of assessment on May 12, 2011 your 2010 return is open for audit until May 12, 2015. The regulations state that you should keep all tax related documents, including T-slips, for at least six years. This includes copies of T-slips sent with your tax return.

In the second half of the year the CRA undertake matching where they start with all the T slips reported by employers, banks and trusts and match these to the amounts reported by individual tax payers.

What I think Steve_ meant was that if your return just consisted of T-slips and survived matching it is highly unlikely to be selected for audit unless the CRA become aware of other circumstances.

Probably worth $10 not to have to bother copying anything. Just chuck all the receipts and slips in an envelope and "file" it in the shoebox under the bed, and hope to god I never have to dig it out again under duress!

I'd been in Canada for a grand total of 3 months and my business got audited, with a 2 day visit from CRA. I've no idea what he managed to fill 2 days with, but he duly took all my original receipts away for 2 months before returning them and declaring all was in order.

I think it was the request for a $80,000 GST refund that raised a red flag.

Yeah I had the CRA phone me up and question me at length as to why my GST return showed that they owed me money, basically start-up costs outweighed any collected at that point, so they were okay with it.

Well speak of the Devil, it appeared in the post yesterday so all is well.