Hello,
You are looking for the Schedule 125 Income Statement Information, it will be in the first section for Revenue under the line 8089 in the second section. Select the drop down menu under the Code column and scroll down to code 8100 Interest income(financial Institutions).
No. Do not use GIFI code 8100 (or any GIFI code between 8100 and 8103) unless your company is in the finance or insurance industry!
For companies NOT in the finance or insurance industry (i.e. MOST companies), just use GIFI code 8090 for passive interest income earned from your Canadian bank account(s).
I should add that in some cases, interest income from a corporate chequing account can be treated as "incidental active" income and taxed at a lower rate! In that case, do not use GIFI code 8090. Instead use a GIFI code your company typically uses for revenue (e.g. GIFI Code 8000) for the "incidental active" interest income.
RULE OF THUMB: Interest income from the company's operating chequing account can often be considered "incidental active" income but only if the amount of money typically held in the operating chequing account is reasonable for the company's operations. In this case, use a GIFI code your company typically uses for revenue (e.g. GIFI Code 8000) for the "incidental active" interest income generated in your company's chequing account
RULE OF THUMB: Interest income from "excess cash" held in the operating chequing account should be treated as "investment passive" income and taxed at a higher rate. In this case, use GIFI code 8090 for the interest income generated from the "excess cash".
NOTE: Interest income from a corporate savings account or GIC would typically be considered "investment passive" income. In that case, use GIFI code 8090. "Investment passive" income is taxed at a higher rate.
See
https://empirecpa.ca/tax-treatment-of-interest-income/
P.S. Nowadays, most chequing accounts do not earn any interest. So the distinction between "incidental active" income and "investment passive" income is really not an issue.