Yes! You can use AI to fill out Form T2125, Statement of Business or Professional Activities

Filers often incorrectly fill out both Part 3A (Business income) and Part 3B (Professional income) on the same form, or use the wrong section for their income type. The form explicitly states that a separate T2125 is required for each. This mistake can lead to incorrect income calculations and processing delays by the CRA. To avoid this, carefully determine if your income is from a business (e.g., retail, construction) or a profession (e.g., accounting, medical) as defined in Guide T4002, and use a separate form for each.

A frequent error is entering net sales (after taxes) into line 3A, which asks for gross sales including GST/HST. Filers then have nothing to deduct on line 3B, leading to an incorrect 'Adjusted gross sales' figure. This miscalculation can affect the entire income statement and may trigger a review. Always report the total amount billed to customers on line 3A and then subtract the collected GST/HST and other adjustments on line 3B.

Many people leave the 'Industry code' field blank or guess at the number because finding the correct one in the T4002 guide can be time-consuming. An incorrect or missing code can flag the return for review or result in the CRA misclassifying the business, potentially impacting future risk assessments. It is crucial to look up and enter the specific six-digit code that best describes your main business activity. AI-powered tools like Instafill.ai can help by suggesting codes based on your 'Main product or service' description.

Chart A for motor vehicle expenses is a common source of errors, particularly in calculating the business-use percentage. Filers often fail to keep a detailed log of kilometres, leading to an inaccurate or indefensible ratio of business vs. total kilometres (lines 1 and 2). This can result in disallowed expenses during an audit. To prevent this, maintain a contemporaneous logbook throughout the year and accurately transfer the totals to the form to calculate the deductible portion of your vehicle expenses.

When claiming home office expenses in Part 7, people often make two key mistakes: incorrectly calculating the percentage of the home used for business, or claiming expenses that create or increase a business loss. The deduction is limited to the net income of the business before this claim. Claiming an excessive amount or using it to generate a loss will be disallowed, and the incorrect claim can lead to reassessments. Ensure your calculation of the workspace area is reasonable and defensible, and remember that you can only carry forward unused expenses to future years.

Area A for CCA is the most complex part of the form, leading to numerous errors. Common mistakes include using the wrong CCA class for an asset, incorrectly carrying over the Undepreciated Capital Cost (UCC) from the previous year, or misapplying the half-year rule or the newer, more complex rules for immediate expensing (DIEP) and accelerated investment incentives (AIIP). These errors can significantly misstate net income and may lead to penalties. Double-checking calculations and asset classes is critical.

Self-employed individuals often mistakenly claim the full amount for expenses that have a personal component, such as cell phone bills, home internet, or insurance. The form requires filers to 'enter only the business part' of expenses. Failing to prorate these costs accurately can lead to an over-claim of deductions and potential reassessment with interest and penalties upon review. It is essential to keep detailed records that justify the business percentage claimed for each shared expense.

In Part 2, filers may forget to list all income-generating web presences, such as third-party platforms (e.g., Etsy, Amazon, Uber), social media pages, or secondary websites. They may also provide an inaccurate estimate for the percentage of income generated online. The CRA uses this data for analytics, and omissions could trigger further questions. It's important to provide a complete list of all URLs and a reasonable, good-faith estimate of the income percentage derived from them.

Filers sometimes enter the fiscal period dates incorrectly, either by using a standard calendar year when their business has a different year-end or by failing to use the required YYYYMMDD format. This can cause processing errors and mismatches with the CRA's records. Always verify your business's official fiscal period and enter the start and end dates precisely as instructed. AI-powered form-filling tools like Instafill.ai can help prevent this by validating the date format automatically.

The instructions clearly state, 'For each business or profession, fill in a separate Form T2125.' However, individuals with multiple self-employment ventures, such as a consulting service and a retail side-business, sometimes try to combine them onto a single form. This leads to inaccurate reporting of income and expenses for each distinct operation, making the return difficult for the CRA to process and assess. Always use one T2125 for each unique business to ensure clarity and compliance.