Tax Planning for Legal Firms in Canada | Custom CPA
⚖️ Legal Industry Tax Strategy
Tax Planning for Legal Firms in Canada
📌 Quick Summary
Tax planning for Canadian law firms and legal practices is one of the most nuanced professional services tax environments in Canada — combining the unique economics of legal billing, professional corporation rules specific to lawyers, complex Law Society trust accounting obligations, partnership income allocation, and restrictive TOSI (Tax on Split Income) rules that significantly limit income splitting opportunities. Yet well-executed tax planning for a successful Canadian lawyer or law partnership can save $50,000–$200,000+ per year in combined corporate and personal tax. This comprehensive guide covers every major tax planning strategy available to Canadian legal practices — from solo practitioners to large multi-partner firms.
1. The Legal Firm Tax Planning Landscape
Canadian law firms operate within a tax planning environment shaped by four intersecting realities: high personal income (senior lawyers frequently earn $300,000–$1M+ in billable fee income); the availability — and restrictions on — professional corporation structures; the unique billing and cash flow dynamics of legal practice (retainers, contingency fees, trust accounts); and the mandatory Law Society compliance obligations that affect how money flows through the practice.
The potential tax saving from proactive legal firm tax planning is among the highest of any professional service — precisely because the income levels are high and the marginal tax rate differential between a 9% corporate rate and a 50%+ personal rate is so large. A lawyer earning $600,000 in net professional income who is operating as a sole proprietor is paying $200,000–$250,000 more in annual tax than the same lawyer operating through a well-structured Professional Corporation. Over a 25-year career, that difference compounds to $5M–$6M in lifetime tax.
Potential annual tax saving for a lawyer with $500K income operating through a well-structured PC vs. sole proprietorship
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9%
Combined federal/provincial corporate tax rate on the first $500K of active PC income — vs. 50%+ personal marginal rate
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TOSI
Tax on Split Income rules — significantly restrict income splitting through lawyer professional corporations since 2018
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$1.25M
Lifetime Capital Gains Exemption — potentially available on sale of qualifying PC shares, saving $300K–$350K per shareholder
⚖️ Is Your Law Firm's Tax Structure Optimized for Your Income Level?
Custom CPA provides specialized tax planning services for Canadian lawyers and legal firms — professional corporation strategies, TOSI analysis, billing timing, and year-end optimization that keeps more of your earnings.
2. Professional Corporation — The Foundation of Legal Tax Planning
The Professional Corporation (PC) is the single most impactful tax planning tool available to a Canadian lawyer with net professional income consistently above $100,000. The mechanics are straightforward: the PC earns the professional income at the low corporate rate, and the lawyer-owner withdraws only the amount needed for personal living — deferring tax on the balance until retirement or when rates are more favourable.
Tax Rate Comparison — Sole Proprietor Lawyer vs. Professional Corporation (Saskatchewan, 2024)
Sole prop — income $200K
~47% combined marginal rate on top earnings
~47%
Sole prop — income $500K+
~53% marginal rate on all income above $235K
~53%
PC — active income (SBD)
~9% on first $500K (SBD rate)
~9%
PC — income above SBD limit
~27% on income above $500K (general rate)
~27%
PC Strategy
How It Works
Annual Tax Benefit
Requirements
Small Business Deduction (SBD)
Active legal income up to $500K taxed at ~9% vs. 50%+ personal rate
$160,000–$180,000/year on $400K above personal needs
Active business income; CCPC status; income below associated corp SBD threshold
Health Spending Account
PC funds an HSA providing tax-free medical benefits to lawyer and family
$5,000–$25,000 in tax-free benefits annually
Set up formal HSA; T4 Box 40 reporting; benefits must be reasonable
LCGE on share sale
Qualifying QSBC shares sheltered by $1.25M LCGE per shareholder on exit
$300,000–$350,000 tax saved per qualifying shareholder on retirement sale
QSBC qualification; 24-month holding; corporate purification of passive assets
Retirement savings inside PC
Retained earnings invested inside PC at 9% tax; compound for retirement
20–40 year compound advantage on deferred tax savings
Passive income rules (RDTOH, GRIP); monitor SBD grind from passive income
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Law Society Requirements for Professional Corporations: Each provincial law society regulates how lawyers may structure their professional corporations. Requirements typically include: the PC must be wholly or substantially owned by the lawyer or other licensees; the PC name must include the words "Professional Corporation" or "PC"; the PC must maintain professional liability insurance; and the lawyer remains personally liable for professional negligence regardless of the PC structure. Confirm your provincial law society's specific requirements (LSO in Ontario, LSBC in BC, LSA in Alberta, etc.) before incorporating. Our Legal Firm Bookkeeping guide covers the Law Society compliance layer in detail.
3. Salary vs. Dividend Optimization
Once a lawyer has incorporated, the annual decision about how much salary and how many dividends to draw from the PC is one of the most important tax decisions each year. The optimal mix differs depending on the lawyer's income level, personal tax situation, RRSP contribution room, CPP entitlement, and whether the TOSI rules affect dividend payments to family members.
Factor
Argues for Salary
Argues for Dividends
RRSP contribution room
Salary creates 18% RRSP room on earned income — valuable for retirement savings
Dividends do not create RRSP room — disadvantage for lawyers who value RRSP
CPP contributions
Salary triggers CPP contributions — provides pension entitlement at retirement
No CPP on dividends — saves current cost but reduces CPP pension
Combined tax rate
Salary is deductible to PC; combined rate (corporate deduction + personal income tax) may be lower in some scenarios
Eligible dividends (from general rate income pool) often achieve better combined rate than salary for top-rate taxpayers
SBD income preservation
Higher salary reduces corporate income, which may allow more income to benefit from SBD rate if approaching $500K limit
Leaving income in PC at 9% SBD rate and drawing dividends later defers high personal tax
Simplicity
Salary is straightforward; requires T4 and payroll remittances; no dividend declaration process
The Tax on Split Income (TOSI) rules, introduced in 2018, significantly restricted the ability of lawyers to split income with family members through their professional corporations. Before TOSI, paying dividends to a spouse or adult children who held shares of the PC was a common and effective income-splitting strategy. Today, TOSI subjects split income to the highest marginal rate unless a specific exclusion applies.
📋 TOSI Exclusions That May Apply to Lawyer PCs
Reasonable compensation exclusion — dividends paid to a family member are excluded from TOSI if they represent reasonable compensation for services the family member actually provided to the law firm (e.g., spouse works as office manager, receptionist, or paralegal). Must be documented and the amount must be reasonable for the services provided. Most Common Exclusion
Spouse age 65+ exclusion — if the lawyer (the source individual) is 65 or older, income splitting with their spouse is excluded from TOSI. This was the pre-2018 "pension income splitting" equivalent for corporate income. Retirement Strategy
Safe harbour return on invested capital — if a family member has invested actual capital (at fair market value) into the PC, a return up to a prescribed rate on that investment may be excluded from TOSI. Rarely applicable to most legal PCs. Limited Application
Adult children working in the firm — dividends paid to adult children who work in the firm for a reasonable number of hours may be excluded if their compensation is reasonable for their contribution. Must be genuinely employed, not just shareholders. Heavily Scrutinized
Excluded shares (not typically available to professional corporations) — a broader exception exists for companies where the shareholder is actively involved, not a professional corporation. Most law firm PCs do not qualify for this exclusion. Rarely Applies to Law PCs
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TOSI Analysis Is Fact-Specific: The TOSI rules are among the most complex provisions in the Income Tax Act, and their application to a specific law firm structure depends on facts that may have changed since the PC was established. An income splitting arrangement that worked in 2017 may now be fully subject to TOSI. Every legal professional corporation should have its TOSI position reviewed annually by a CPA. Incorrectly claiming TOSI exclusions without proper documentation exposes both the lawyer and the family member shareholder to reassessment and penalties.
5. Billing & Payment Timing Strategies
Billing and payment timing is a powerful tax planning lever for law firms — particularly for unincorporated sole practitioners and partnerships that can time revenue recognition. Even for incorporated lawyers, the timing of trust-to-general transfers (when earned fees are transferred from the trust account) affects when income is recognized. Here is how timing strategies work in practice:
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Year-End Billing Deferral
For lawyers using cash or billing basis accounting, deferring December invoices to January pushes revenue to the next fiscal year — reducing current-year taxable income. Effective in high-income years to smooth income across years.
High Impact
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Trust-to-General Transfer Timing
For both sole proprietors and PCs, the transfer of earned fees from the trust account to the general account is when income is typically recognized. Timing large fee transfers before or after year-end can move significant income between tax years.
Timing Opportunity
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Contingency Fee Timing
Contingency fees (typically received on successful litigation conclusion) are recognized when the right to receive the fee is established. Multi-year contingency matters offer natural income timing opportunities — discuss recognition timing with your CPA before settlement.
Complex Area
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WIP Year-End Review
Work in Progress (unbilled time) at year-end is generally not taxable until billed and collected. A deliberate WIP management strategy — letting WIP accumulate before billing — defers income. Must be consistent with Law Society billing obligations.
Deferral Tool
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Retainer Management
Retainers deposited into trust are not income when received — only when earned and transferred. Managing the pace of retainer drawdown (as fees are earned) against the fiscal year-end date creates timing flexibility.
Trust Planning
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Income Averaging Across Years
Lawyers with volatile income (large contingency wins, real estate closings) benefit from averaging strategies — maintaining consistent personal draws while letting corporate retained earnings accumulate in high-income years and draw down in lower years.
PC Strategy
📊 Is Your Law Firm's Billing Timing Optimized for Tax?
Custom CPA models year-end billing timing, trust-to-general transfer schedules, and contingency fee recognition strategies to legally minimize your law firm's annual tax bill.
Law partnerships — including partnerships of lawyers and partnerships of professional corporations — have distinct tax planning considerations that don't apply to solo practitioners. The partnership is a flow-through entity for tax purposes, meaning all income, deductions, and credits flow to the individual partners (or their PCs) according to the partnership agreement allocation formula.
Partnership Tax Issue
Key Planning Consideration
CPA Action Required
Income allocation formula
Partnership agreement must specify the basis for income allocation (hours, seniority, origination, equity). CRA scrutinizes allocations that don't reflect economic reality — particularly if a lower-income partner receives a disproportionate share to reduce overall tax burden.
Review allocation formula annually for CRA compliance; ensure formula is documented and consistently applied
Partner PC structures
Partners may operate through their own PCs — each PC receives its share of partnership income and pays corporate tax at the SBD rate. Requires partnership agreement to permit PC participation and law society compliance
Confirm law society rules permit partnerships of PCs; review partnership agreement for PC provisions
T5013 partnership return
The partnership must file a T5013 information return annually (regardless of income) and issue T5013 slips to each partner showing their allocated share of income, deductions, and credits
Annual T5013 preparation; ensure all partner slips are accurate and filed by deadline
Partner buy-in (joining the firm)
When an associate becomes a partner, they typically pay for their partnership interest. The allocation of that cost between goodwill, capital, and other partnership assets has significant tax implications for both the incoming partner and the existing partners
Model the buy-in structure before finalizing; analyze capital gains vs. income treatment; consider ACB adjustments
Partner retirement / buy-out
Retiring partners may receive a lump-sum retirement allowance (partially deductible, partially taxable) and/or a sale price for their partnership interest. LCGE may apply if the interest qualifies as a QSBC interest
Model retirement payment structure; assess LCGE qualification; plan over multiple years if possible
7. GST/HST for Legal Services
Legal services in Canada are fully taxable for GST/HST purposes — with limited exceptions. Law firms must register for GST/HST when annual taxable supplies exceed $30,000 and must collect the applicable rate from clients. For law firms with complex multi-provincial practices and international clients, the place of supply rules and export zero-rating provisions require specific attention. For e-commerce law firms or those with online subscription services, our E-Commerce GST/HST guide covers the digital service compliance layer.
🌐 GST/HST Key Rules for Canadian Law Firms
All legal fees are taxable supplies — GST/HST applies to all legal fees, disbursements billed to clients (even if the original disbursement wasn't taxed), and any other charges in the legal invoice. The rate is based on the province where the client is located. Fully Taxable
Legal services to non-residents may be zero-rated — services provided to a non-resident client who is outside Canada when the service is provided may be zero-rated, unless the service relates to real property or goods situated in Canada. Confirm with your CPA for each non-resident client engagement. Zero-Rating Possible
Contingency fees — GST/HST collected on billing date — when a contingency fee is earned and billed, GST/HST is due on the full amount in that billing period. For large contingency fees, this can create a significant GST/HST remittance due in the same quarter — plan cash flow accordingly. Cash Flow Impact
Disbursements are generally taxable when billed — court filing fees (which may have been paid without GST), courier costs, title search fees, and other disbursements billed to clients are generally treated as consideration for a separate taxable supply — GST/HST applies on the full invoice including disbursements. Common Error Area
Full ITCs on all firm expenses — law firms recover 100% of GST/HST paid on all taxable business expenses: office rent, software, library subscriptions, equipment, professional fees, and contractor services. For most law firms, these ITCs significantly reduce the net GST/HST remittance. Full ITC Recovery
8. Key Tax Deductions for Legal Firms
Law firms are entitled to deduct all expenses reasonably incurred to earn professional income. Here are the most significant deductions — with legal-sector-specific guidance:
Expense Category
Legal Firm Notes
Deduction Treatment
Law Society fees & professional dues
Annual licensing fees, LSO/LSBC/LSA registration; continuing legal education required to maintain licence; professional liability insurance (LAWPRO, CLIA, etc.)
100% deductible — current period operating expense
Subscriptions: 100% current expense; perpetual licences may be capitalized as Class 12 (100% CCA)
Office space and lease costs
Full commercial office space rent is deductible; home office deductions available for lawyers working from home — based on proportionate area and verified use
Commercial rent: 100% deductible; home office: prorated by business-use percentage
Associate and staff compensation
Associate lawyer salaries, paralegal wages, legal assistant wages, office manager compensation — all deductible if reasonable and documented
100% deductible including employer CPP/EI; T4 required for all employed staff
Meals and entertainment (limited)
Client lunches, bar association events, networking dinners — the 50% limitation on meals and entertainment applies. Must have a genuine business purpose and the client/business purpose documented.
50% deductible — the other 50% is a permanent non-deductible amount
Books, journals, and library costs
Legal textbooks, law reports, practice guides, and professional journals — fully deductible. Physical books may be capitalized as Class 12 (100% CCA) or expensed if under the materiality threshold.
Subscriptions: 100% current; books: Class 12 (100% CCA) or current if immaterial
9. Year-End Tax Planning Checklist for Legal Firms
Year-end tax planning for a law firm must begin at least 60–90 days before the fiscal year-end — many of the most effective strategies require action before the year closes. For agriculture businesses that may be law firm clients, our Agriculture Tax Services guide provides context on client-specific tax planning. Our Specialized Services and Strategic CFO Advisory Services include annual legal firm tax planning as a core deliverable.
📅 Legal Firm Year-End Tax Planning Checklist
Model optimal salary vs. dividend split for the year — before year-end, calculate net PC income and model the tax-minimizing owner compensation mix. Salary paid before December 31 affects RRSP room and CPP for the current year. Priority Action
Review billing timing and WIP — in high-income years, defer December billings to January. Review the WIP schedule and identify matters where billing can legitimately be delayed without client relationship impact. Income Timing
Declare any employee bonuses before year-end — year-end staff bonuses formally declared before fiscal year-end are deductible in the current year (payable within 180 days). Must be formally documented — not just an intention. Document Bonus
Fund Health Spending Account before year-end — corporate HSA contributions must be made before year-end to be deductible in the current fiscal year. Plan the annual benefit amount with your CPA. Tax-Free Benefit
Review TOSI positions for all family shareholder dividends — confirm that any dividends paid to family members during the year are supported by a qualifying TOSI exclusion. Retroactive assessment risk if documentation is not in order. TOSI Review
Confirm SBD limit — passive income grind-down — if the PC has significant passive investment income (above $50,000), the SBD limit may be grinding down. Calculate the impact and consider strategies to distribute excess passive income before year-end. SBD Monitoring
GST/HST annual reconciliation — confirm total GST/HST collected per billing system matches GST/HST filed for the year. Confirm all disbursements have been treated correctly. Resolve any discrepancies before year-end if possible. Compliance
Review QSBC qualification for LCGE planning — confirm the PC's assets are at least 90% active business assets and the 24-month holding conditions are met. Address any passive asset accumulation before it disqualifies the LCGE. Exit Planning
✅ Custom CPA — Tax Planning Services Built for Canadian Legal Practices
Professional corporation structuring, TOSI analysis, billing timing optimization, partnership tax planning, GST/HST compliance, and comprehensive year-end tax strategies — for lawyers and legal firms of every size.
Should a Canadian lawyer incorporate as a professional corporation?
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Most Canadian lawyers whose net professional income consistently exceeds $100,000 benefit significantly from incorporating as a Professional Corporation. The economics are straightforward: The Small Business Deduction reduces corporate tax to approximately 9% on the first $500,000 of active legal income — compared to combined federal/provincial personal marginal rates of 47–53% for high-income lawyers in most provinces. On $300,000 of income above the lawyer's personal living needs, the annual tax deferral is approximately $110,000–$130,000. Over a 25-year career at that income level, the compounding effect of that deferred tax is transformative. Additional benefits: the corporation can fund a Health Spending Account providing tax-free medical benefits; salary paid from the PC creates RRSP contribution room; and if the PC qualifies as a Qualified Small Business Corporation, shares sold on retirement may be sheltered by the Lifetime Capital Gains Exemption ($1.25M+ per shareholder). Important considerations: TOSI rules since 2018 have significantly restricted income splitting through lawyer PCs — so the corporate structure primarily benefits the lawyer personally, not family members in most cases; the Law Society in each province has specific requirements for professional corporations (wholly owned by licensees; named appropriately; liability remains with the lawyer); and the additional compliance cost (annual T2, separate corporate bookkeeping) must be weighed against the tax benefit — generally the break-even point is around $80,000–$100,000 of net professional income. Confirm the economics for your specific situation with a CPA before incorporating.
Can a Canadian lawyer split income with their spouse through a professional corporation?
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Income splitting through a lawyer's professional corporation is significantly more restricted since the Tax on Split Income (TOSI) rules were introduced in 2018. Before TOSI, paying dividends to a spouse or adult children who held shares of the PC was a common and effective strategy — potentially saving $15,000–$40,000 per year. Today, most income splitting arrangements through lawyer PCs are subject to TOSI, which taxes the recipient's dividend at the highest marginal rate (effectively eliminating the income splitting benefit). Situations where income splitting may still work: (1) Reasonable compensation to a working spouse: if the spouse genuinely works in the law firm (as receptionist, office manager, billing coordinator, paralegal, etc.) and receives dividends or salary that is reasonable for their actual contribution, TOSI does not apply to that amount. Documentation of the actual services performed and an arm's-length compensation analysis is essential. (2) Lawyer is 65 or older: once the lawyer reaches age 65, dividends paid to their spouse are excluded from TOSI — the pre-2018 income splitting opportunity re-opens at retirement age. (3) Adult children working in the firm: where adult children are genuinely employed in the firm and receive compensation reasonable for their contribution, dividends within that reasonable amount may avoid TOSI. The TOSI analysis is highly fact-specific — whether your specific situation qualifies for an exclusion must be assessed by your CPA based on the actual structure, the family member's involvement, and documented compensation rationale. Never pay family dividends without completing a formal TOSI analysis first.
How should a law firm time billing and payments for tax purposes?
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Billing and payment timing is one of the most accessible and effective tax planning tools for Canadian law firms — particularly for sole practitioners and partnerships using cash or billing basis accounting. How revenue timing works for unincorporated lawyers: Under cash basis, income is recognized when received. Under billing basis (more common), income is recognized when billed. This gives an unincorporated lawyer substantial control over when income is recognized: deferring December billing to January in a high-income year pushes that revenue to the next tax year; accelerating billing in a low-income year (e.g., following parental leave) brings revenue forward into a lower-rate year. Trust account timing: for both sole proprietors and incorporated lawyers, the trust-to-general transfer — when earned fees are moved from the client trust account to the firm's operating account — is typically when income is recognized for accounting purposes. Timing large fee transfers (e.g., a large real estate or estate closing) before or after year-end can move significant income between tax years. This must always be consistent with Law Society obligations — fees can only be transferred once earned. WIP management: Work in Progress (unbilled time) is generally not taxable until billed and collected. Strategically managing the pace of billing on long-running matters — consistent with the client relationship and engagement terms — defers income recognition. Contingency fees: contingency fees are typically recognized when the right to receive them is established (usually on settlement or judgment). For large contingency matters, this creates an income spike that should be anticipated and planned for. For incorporated lawyers: personal income timing is controlled primarily through salary (timing of payroll) and dividend declaration dates — the corporate income itself is recognized under accrual accounting, but personal withdrawals from the PC can be timed strategically.
Do Canadian law firms need to charge GST/HST on legal services?
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Yes — legal services in Canada are fully taxable supplies for GST/HST purposes. Law firms must register for GST/HST when their annual taxable supplies exceed $30,000 and must collect and remit GST/HST on all legal fees charged to clients. The applicable rate depends on the province where the service is supplied (generally the client's province): Ontario 13%; most Maritime provinces 15%; Alberta 5%; BC, Saskatchewan, Manitoba 5% GST (plus separate provincial PST registration may be required for those provinces). What is taxable: all legal fees (hourly billing, fixed fees, contingency fees); disbursements billed to clients (court filing fees, process server costs, courier, photocopying, title search fees) — even if the original expense was not subject to GST/HST, the billed disbursement is generally part of the taxable supply; and any ancillary charges on the invoice. What may be zero-rated (0% GST/HST): legal services provided to a non-resident client who is outside Canada at the time the service is supplied, AND where the service is not in respect of real property in Canada, goods in Canada, or services performed in Canada. A Canadian law firm providing advice on international law to a foreign client without any Canadian law element may qualify — but the same firm advising on a Canadian real estate transaction for a foreign buyer cannot zero-rate the service. Confirm zero-rating eligibility per engagement with your CPA. Input Tax Credits: law firms recover all GST/HST paid on their own business expenses (office rent, legal research subscriptions, technology, professional fees, Law Society fees) through ITCs, reducing the net GST/HST payable.
What are the tax implications of a law firm partnership in Canada?
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A Canadian law partnership (whether a general partnership, limited liability partnership — LLP, or partnership of professional corporations) is a flow-through entity for income tax — the partnership itself does not pay income tax. Instead: each partner's share of partnership income (calculated according to the partnership agreement's allocation formula) flows directly to that partner's personal T1 return or to their professional corporation's T2 return if the partner has incorporated. T5013 annual filing: every Canadian partnership must file a T5013 information return with CRA annually. The T5013 shows the partnership's total income and deductions, along with a breakdown of each partner's allocable share. Each partner receives a T5013 slip that they include in their own tax return. This is an additional filing obligation on top of each partner's personal (or corporate) return. Partnership income allocation: the partnership agreement governs how income is allocated between partners — typically based on hours, seniority, origination of clients, or fixed equity shares. CRA will challenge allocations that appear to shift income from high-rate to low-rate partners without economic substance. Partner buy-in tax implications: when an associate lawyer joins a partnership as a partner, they pay for their partnership interest. The tax treatment depends on what they are acquiring — typically a combination of capital assets (goodwill, equipment) and income-generating activities. Goodwill paid on a partner buy-in may be a capital expenditure for the incoming partner; existing partners may recognize capital gains on the sale of their proportionate interest. The structure of the buy-in should be analyzed by a CPA before finalizing. Retirement / departure: when a partner retires or leaves, the retirement allowance (paid by the firm) and any purchase of the departing partner's interest have specific tax treatments. Amounts classified as for "eligible years of service" may be transferred to an RRSP beyond the normal limit; the sale of the partnership interest may attract capital gains with potential LCGE eligibility. All partnership entry and exit transactions require CPA analysis.
Disclaimer: The above contents are provided for general guidance only, based on information believed to be accurate and complete, but we cannot guarantee its accuracy or completeness. It does not provide legal advice, nor can it or should it be relied upon. Please contact/consult a qualified tax professional specific to your case.
