CRA will find out when they audit the restaurant.
https://www.canada.ca/en/revenue-agency/campaigns/track-report-tips-gratuities/tips-gratuities-taxable.html
Are you aware that all your tips and gratuities are taxable?
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Restaurant and bar servers, hairdressers, valets, taxi drivers and others who earn tips need to be sure those amounts are included as income when they file their income tax and benefit returns.
If you receive tips or gratuities as part of the type of work you do, this information is for you.
Keep track of all your tips and gratuities received throughout the year (for example, on a calendar, a mobile app or in an agenda)
Calculate the total received between January 1 and December 31
Report the total amount received on line 10400 of your income tax and benefit return
In Canada, the law is clear about the treatment of income received from tips and gratuities: all tips and gratuities are taxable, and it is your responsibility to track and report any amounts received.
How to report your tips
Enter the total amount of tips you received during the year on line 10400 of your income tax and benefit return. If you are an employee, tip income might already be included on your T4 slip. If you’re not sure, ask your employer.
If you report all your tips and gratuities, you will see the following benefits
The additional income you report can be an advantage to you when applying for a loan or mortgage
Tips qualify as earned income for purposes of registered retirement savings plan (RRSP) contribution limits–you will be able to invest more, and deduct more, in RRSPs
You can choose to pay Canada Pension Plan (CPP) or Quebec Pension Plan (QPP) contributions, which will increase your CPP or QPP pension amounts when you retire
https://www.ctvnews.ca/canada/tax-crackdown-finds-many-servers-not-declaring-tips-1.870411
OTTAWA - A blitz by Canada Revenue Agency auditors on an unfortunate group of waiters and waitresses in one Ontario community has exposed "very surprising" amounts of unreported tips and gratuities.
The pilot project targeted 145 servers working in just four restaurants in St. Catharines, Ont., a blue-collar city on the Niagara Peninsula, south of Toronto.
Auditors reviewed two years' worth of income and found that every individual had hidden some portion of their tips from the taxman, with about half reporting no tips whatsoever.
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In the end, the blitz flushed out $1.7 million in unreported tips and gratuities -- almost $12,000 for each person.
"Industry insiders often tell servers that they only need to report 10 per cent of their ... wages as tip income," says an internal report on the project.
"Our results indicate that tips are more likely to be 100 per cent to 200