Simplified ITC Method

Definition

The Simplified ITC Method is an optional calculation under the Streamlined Accounting (GST/HST) Regulations that lets an eligible small registrant determine its total Input Tax Credits for a reporting period by multiplying its total tax-included eligible purchases by a fraction matching the applicable rate, rather than isolating the GST/HST shown on each individual receipt. The underlying ITC entitlement under ETA s.169 is unchanged; only the arithmetic is simpler.

Key rules

• Eligibility: annual worldwide taxable supplies (plus associates) must not exceed $1,000,000 for the current and preceding fiscal year, and total taxable purchases (excluding zero-rated) must not exceed $4,000,000 for the preceding fiscal year. Charities and selected public bodies have separate thresholds.
• No formal election is required. The registrant simply applies the method consistently in a reporting period.
• Calculation: separate purchases by tax rate, total each group including tax, and multiply by the corresponding fraction.

• Eligible purchases include only amounts used in commercial activity, so any personal-use or exempt-use share must be excluded before the fraction is applied. Non-claimable items (50% disallowed meals, club memberships) must also be excluded.
• Documentary requirements under Reg 3501 still apply. The simplification affects the math, not the records.
• Capital property can be included in the simplified calculation to the extent the asset is used more than 50% in commercial activity (primary-use test).

Example

A BC corporation that delivers services into BC, Ontario, and New Brunswick tallies its eligible tax-included purchases for Q2 2026:

Purchases on which 5% GST was paid (BC vendors):   $21,000
Purchases on which 13% HST was paid (ON vendors):   $6,780
Purchases on which 15% HST was paid (NB vendors):   $2,300

Simplified ITC calculation
5/105 × $21,000 = $1,000.00
13/113 × $6,780 =   $780.00
15/115 × $2,300 =   $300.00
Total ITCs on line 108:                           $2,080.00

If 20% of the BC purchases were personal-use, the BC figure would first be reduced to $16,800 before applying the 5/105 fraction, yielding $800 of ITCs instead of $1,000.

Common mistakes

• Applying the 5/105 fraction to a tax-exclusive total. The Simplified Method assumes the figure includes GST/HST.
• Mixing rates in one pool. ON purchases at 13% and BC purchases at 5% must be totalled separately before their own fractions are applied.
• Forgetting to strip out the 50% non-deductible portion of meals and entertainment, or inputs used for exempt supplies.
• Using the method despite exceeding the $1M revenue or $4M purchase ceilings.
• Skipping source documents. The simplified math does not waive the documentary requirements of Reg 3501.

Related concepts

The Simplified Method is one of three ITC approaches: it is the middle option between the regular line-by-line ITC claim and the flat Quick Method. Documentation must still meet the Reg 3501 thresholds.