A business card does not make an entire purchase commercial. If a bill supports both work and personal life, the input tax credit calculation needs more than the payment method.
Explain the commercial share
Use a fair, reasonable allocation method and apply it consistently. Keep the evidence behind the percentage: relevant usage records, a work log or another measure suited to the purchase. If the business also makes exempt supplies, distinguish that use from commercial activity. CRA's commercial-use guidance.
Suppose an ordinary eligible operating service costs $100 plus $13 HST, and a supported allocation is 60% commercial use. If the proportional operating-expense rule applies and all other conditions are met, the ITC is $7.80. The example does not establish a standard 60% allowance; its percentage must come from actual use.
Match the rule to the purchase
Capital property, passenger vehicles, meals and business-use-of-home expenses can have special restrictions. Some rules use thresholds rather than a straight proportional claim. Do not apply the service-bill example to a car or building without checking the relevant category. CRA's ITC eligibility percentages.
Keep three entries visible: the total tax, the supported use calculation and the amount actually eligible under the rule. That separation helps explain why an income-tax business-use percentage and the GST/HST claim might differ.
Review the allocation when circumstances change. A subscription used mainly for personal purposes after a business closes, or equipment moved into a different activity, should not retain an old tax code merely because the software remembers it.
Checked October 20, 2026. For the basic eligibility sequence, see input tax credits.
