Superficial Loss Rules

Overview

PrivateACB automatically detects and applies Canada’s superficial loss rule when calculating your Adjusted Cost Base (ACB). This rule prevents taxpayers from claiming a capital loss on a sale if they repurchase the same asset shortly before or after the sale.

Key facts:

The superficial loss rule is mandatory — it cannot be disabled
PrivateACB applies it automatically to all Canadian ACB calculations
Denied losses are not lost — they are added to your ACB and recovered when you eventually sell

Regulatory authority: Canada Revenue Agency (CRA) Legal basis: Income Tax Act — Section 54 (definition), Subsection 40(2)(g)(i) (denial), Subsection 53(1)(f) (ACB increase)

What is a Superficial Loss?

Definition

A superficial loss occurs when all three of the following conditions are true:

You sell cryptocurrency at a loss
You (or a person affiliated with you) acquire the same cryptocurrency within a 61-day window — 30 days before the sale, the day of the sale, or 30 days after the sale
You still own the cryptocurrency 30 days after the sale

If all three conditions are met, the CRA denies some or all of the loss.

What Happens When It Applies

The denied portion of the loss cannot be claimed on your tax return this year
The denied amount is added to your ACB (cost base) of the remaining holdings
When you eventually sell those holdings, the higher ACB will reduce your future capital gain (or increase your future loss)
The loss is deferred, not eliminated

Simple Example

Jan 1:   Buy 1 BTC at $50,000           ACB = $50,000
Feb 1:   Sell 1 BTC at $40,000          Loss = $10,000
Feb 15:  Buy 1 BTC at $38,000           Repurchased within 30 days
Mar 3:   Still own 1 BTC                Still holding 30 days after sale

RESULT:
- Original loss: $10,000
- All three conditions met → Superficial loss applies
- Loss denied: $10,000 (cannot claim this year)
- New ACB: $38,000 + $10,000 = $48,000

Later: Sell 1 BTC at $45,000
- Proceeds: $45,000
- Cost base: $48,000 (includes deferred loss)
- Capital loss: $3,000
  (You've now recovered the original $10,000 loss — $3,000 here
   instead of what would have been a $7,000 gain without the adjustment)

The 61-Day Window

The superficial loss rule looks at a 61-day window around each sale:

30 days BEFORE       Sale Date       30 days AFTER
     |                   |                   |
     v                   v                   v
  Jan 2  ←──────────  Feb 1  ──────────→  Mar 3

Any purchase of the same asset during this 61-day window
can trigger the superficial loss rule (if the Feb 1 sale was a loss
AND you still own the asset on Mar 3).

Examples

Sale Date	Sale at Loss?	Purchase Date	Still Own at Day 30?	Superficial Loss?	Why?
Feb 1	Yes	Feb 15	Yes	Yes	Purchase within 30 days after, still holding
Feb 1	Yes	Jan 10	Yes	Yes	Purchase within 30 days before, still holding
Feb 1	Yes	Mar 10	Yes	No	Purchase more than 30 days after (37 days)
Feb 1	Yes	Feb 15	No	No	Sold everything before day 30
Feb 1	No (gain)	Feb 15	Yes	No	Sale was a gain, not a loss

The Third Condition: Still Owning at Day 30

This is what distinguishes the Canadian rule from a simple “buy-back” check. Even if you repurchase within the window, the rule does not apply if you sell again and own zero of the asset 30 days after the original sale.

Example where the rule does NOT apply:

Feb 1:   Sell 1 BTC at a loss
Feb 15:  Buy 1 BTC (within 30 days)
Feb 25:  Sell 1 BTC (sold everything again)
Mar 3:   Own 0 BTC → Third condition NOT met → Loss IS allowed

The CRA Proration Formula

Unlike the US wash sale rule (which denies 100% of the loss), Canada’s superficial loss rule uses a proration formula that can deny part or all of the loss.

Formula Parameters

The CRA formula uses three values:

Parameter	Meaning	How PrivateACB Calculates It
S	Shares (units) sold in the loss-making disposal	Quantity from the sale transaction
P	Shares (units) purchased within the 61-day window	Sum of all acquisitions within the window
B	Shares (units) still owned at end of the period (30 days after sale)	Your cumulative position at day 30

Proration Ratio

Proration Ratio = MIN(S, P, B) / S

Take the smallest of S, P, and B, then divide by S.

Denied and Allowed Loss

Denied Loss  = |Total Loss| x Proration Ratio
Allowed Loss = |Total Loss| - Denied Loss

Denied Loss is added to your ACB (deferred)
Allowed Loss is what you can claim on your tax return this year

Why Proration Matters

The proration formula means you don’t always lose the entire loss. If you only repurchased a fraction of what you sold, only that fraction is denied.

Worked Examples

Example 1: Full Denial (100%)

You sell everything and buy it all back.

Current holdings: 10 ETH, ACB = $30,000

Mar 1:  Sell 10 ETH at $2,000/ETH     Proceeds = $20,000
        Cost basis: 10 x $3,000 = $30,000
        Raw loss: $10,000

Mar 10: Buy 10 ETH at $2,100/ETH      Within 30 days
Mar 31: Still own 10 ETH               Still holding at day 30

CRA Formula:
  S = 10 (sold)
  P = 10 (purchased in window)
  B = 10 (owned at end)

  Proration = MIN(10, 10, 10) / 10 = 100%

  Denied loss:  $10,000 x 100% = $10,000 (entire loss denied)
  Allowed loss: $10,000 - $10,000 = $0

Result:
  Claimable loss this year: $0
  ACB of 10 ETH: $21,000 + $10,000 = $31,000
  (The denied $10,000 is preserved in your cost base)

Example 2: Partial Denial (50%)

You sell everything but only buy back half.

Current holdings: 100 BTC, ACB = $1,000,000

Jan 15: Sell 100 BTC at $5,000/BTC    Proceeds = $499,750 (after fees)
        Cost basis: 100 x $10,000 = $1,000,000
        Raw loss: $500,250

Jan 20: Buy 50 BTC at $4,000/BTC      Within 30 days
Feb 14: Still own 50 BTC               Still holding at day 30

CRA Formula:
  S = 100 (sold)
  P = 50  (purchased in window)
  B = 50  (owned at end)

  Proration = MIN(100, 50, 50) / 100 = 50%

  Denied loss:  $500,250 x 50% = $250,125
  Allowed loss: $500,250 - $250,125 = $250,125

Result:
  Claimable loss this year: $250,125
  ACB of 50 BTC: $200,000 + $250,125 = $450,125
  Average cost: $450,125 / 50 = $9,002.50/BTC

Example 3: Multiple Repurchases in the Window

Multiple buys within the 61-day window are summed together for the P value.

Jan 15: Sell 100 BTC at a loss of $500,000

Jan 20: Buy 20 BTC     ─┐
Jan 25: Buy 30 BTC      ├─ All within 61-day window
Feb 10: Buy 50 BTC     ─┘
Feb 14: Still own 100 BTC

CRA Formula:
  S = 100
  P = 20 + 30 + 50 = 100  (total purchased in window)
  B = 100

  Proration = MIN(100, 100, 100) / 100 = 100%
  Entire loss denied.

Example 4: No Denial (Condition Not Met)

You sell at a loss but don’t buy back within the window.

Jun 1:  Sell 5 ETH at a loss of $2,000
Jul 15: Buy 5 ETH (44 days later — outside the 30-day window)

CRA Formula:
  No repurchase within 61-day window → Rule does NOT apply
  Full $2,000 loss is allowed

How PrivateACB Handles Superficial Losses

Automatic Detection

When you run a Canadian ACB calculation, PrivateACB automatically:

Examines every sale transaction
Checks if it resulted in a loss (proceeds less than cost basis)
Searches for repurchases within the 61-day window (30 days before through 30 days after)
Checks ownership at 30 days after the sale
If all conditions met, applies the CRA proration formula:
- Calculates S, P, and B
- Determines the denied amount
- Adjusts the capital gain/loss
- Adds the denied amount back to your ACB
- Records the superficial loss in your database

No Toggle Required

Unlike the US wash sale rule (which is optional), the superficial loss rule is mandatory under Canadian tax law. There is no setting to enable or disable it — it is always applied.

Where to See Superficial Loss Results

After running a Canadian calculation, you can find superficial loss information in several places:

1. Calculation History (Zone D)

The Sup.Loss column in the Calculation History panel shows how many sales triggered the superficial loss rule for each asset. A value of “0” means no superficial losses were detected.

2. Superficial Loss Report (PDF)

The dedicated Superficial Loss Report provides full detail for each affected transaction:

Go to the Reports tab (Ctrl+5)
Select the Canada section
Click Superficial Loss Report

The report includes:

Section	What It Shows
Explanation box	Plain-language description of the rule and ITA references
Transaction table	Each affected sale: asset, date, quantity, proceeds, cost basis, potential loss, denied loss, reason
Summary	Total denied losses, total ACB increase, affected assets count, current-year vs. prior-year breakdown
Tax impact	Immediate effect (loss denied) and future benefit (added to ACB)

Export to PDF or CSV for your records or accountant.

3. ACB Summary Report

The transaction-by-transaction ACB Summary highlights rows where the superficial loss rule was applied with a yellow background. A summary note shows the total denied losses.

4. Schedule 3 (Capital Gains and Losses)

Schedule 3 shows the adjusted gain/loss amount — the loss after proration. Transactions affected by the superficial loss rule are flagged.

5. Data Viewer

In the Data Viewer tab (Ctrl+3), you can inspect the underlying database tables:

Table	What to Look For
superficial_losses	Each detected superficial loss: disposal date, loss amount, denied amount, proration ratio, S/P/B values, window dates
capital_gains	`superficial_loss_applied` column (1 = rule applied, 0 = not)
acb_transaction_records	Running ACB after each transaction (includes superficial loss adjustments)

Common Scenarios

Scenario 1: Active Trader with Frequent Buy-Sell Cycles

Situation: You trade BTC regularly, sometimes selling at a loss and buying back within days.

What happens: Each loss-making sale followed by a repurchase within 30 days triggers the superficial loss rule. The more frequently you trade, the more losses may be denied.

After calculation:

Check the Sup.Loss count in Zone D
Generate the Superficial Loss Report to see exactly which sales were affected
Review the denied amounts and how they increased your ACB

Scenario 2: Year-End Tax-Loss Harvesting

Situation: In December, you sell cryptocurrency at a loss to offset gains, then buy back in January.

What happens: The January repurchase is within 30 days of the December sale. If you still hold the asset 30 days after the sale, the loss is denied.

How to avoid: Wait more than 30 days before repurchasing. If you sell on December 15, don’t buy back until at least January 15.

Scenario 3: Dollar-Cost Averaging Through a Dip

Situation: You buy BTC weekly. The price drops, and you sell some at a loss. Your regular weekly purchases continue.

What happens: Your automatic or regular purchases within the 61-day window count as repurchases, potentially triggering the superficial loss rule even though the buying wasn’t related to the sale.

Key insight: The CRA rule doesn’t consider intent. Any acquisition of the same asset within the window counts, including scheduled or recurring purchases.

Scenario 4: Partial Repurchase

Situation: You sell 10 ETH at a loss, then buy back only 3 ETH within 30 days.

What happens: The proration formula applies:

S = 10, P = 3, B = 3
Proration = MIN(10, 3, 3) / 10 = 30%
Only 30% of the loss is denied; 70% is claimable

This is a key difference from the US wash sale rule, which denies 100% of the loss.

How to Avoid Triggering Superficial Losses

Strategy 1: Wait 31 Days

The simplest approach: after selling at a loss, wait at least 31 days before repurchasing the same cryptocurrency. This moves the repurchase outside the 61-day window.

Strategy 2: Sell Everything Before Day 30

If you do repurchase within the window, you can avoid the rule by selling everything again before the 30th day after your original sale. The third condition (still owning at day 30) won’t be met.

Strategy 3: Be Aware of Recurring Purchases

If you dollar-cost average (buy on a regular schedule), be aware that scheduled purchases can trigger the rule if they fall within 61 days of a loss-making sale. Consider pausing automatic purchases around sales.

Strategy 4: Accept the Deferral

In many cases, the superficial loss doesn’t cost you money — it defers the loss to a future sale. If you plan to hold the repurchased asset long-term, you’ll eventually recover the denied loss through a higher cost base.

Superficial Loss vs. US Wash Sale

If you’re familiar with the US wash sale rule, here are the key differences:

Feature	Canadian Superficial Loss	US Wash Sale
Mandatory	Yes (always applied)	No (optional in PrivateACB)
Ownership check	Must still own at day 30 after sale	No ownership check
Proration	Yes — MIN(S, P, B) / S	No — always 100% denial
Partial denial	Yes (if you repurchased less than you sold)	No (full loss denied)
Tax authority	CRA (Income Tax Act)	IRS (IRC §1091)
Regulatory certainty	Clearly applies to all property including crypto	Uncertain for crypto
Method	ACB (average cost) only	FIFO, LIFO, or HIFO

Tax Efficiency Score

PrivateACB calculates a tax efficiency metric that shows how much of your losses survived the superficial loss rule:

Tax Efficiency = (Total Losses - Denied Losses) / Total Losses x 100%

Score	Rating	Meaning
80-100%	Excellent	Most losses are immediately deductible
60-79%	Good	Some losses deferred to future years
40-59%	Fair	Significant superficial loss impact
Below 40%	Poor	Frequent repurchases triggering denials

A low score doesn’t mean you’re losing money — the denied losses are preserved in your ACB. But it does mean you’re deferring more tax benefit to future years.

Frequently Asked Questions

Q: Can I disable the superficial loss rule?

A: No. Unlike the US wash sale rule (which is optional in PrivateACB), Canada’s superficial loss rule is mandatory under the Income Tax Act. PrivateACB always applies it for Canadian calculations.

Q: Is the denied loss gone forever?

A: No. The denied loss is added to your ACB. When you eventually sell, the higher ACB means a lower capital gain (or higher capital loss). The tax benefit is deferred, not eliminated.

Q: Does the rule apply to each cryptocurrency separately?

A: Yes. Each cryptocurrency is treated as a separate “identical property.” Selling BTC at a loss and buying ETH within 30 days does not trigger the rule. The repurchase must be the same asset.

Q: What if I sell at a loss and the price drops further — can I buy back?

A: You can, but the rule may apply. If you buy back within 30 days and still hold at day 30, some or all of the loss will be denied. However, the denied amount is added to your ACB, so you’ll benefit from it later.

Q: Does the rule apply to all transaction types, or only sell orders?

A: Any disposal that creates a loss. This includes sells, trades (crypto-to-crypto swaps), and any other disposition. The repurchase side includes buys, trades, rewards, staking — any acquisition of the same asset within the window.

Q: What about affiliated persons?

A: The CRA’s superficial loss rule also applies to acquisitions by affiliated persons (spouse, corporation you control, etc.). PrivateACB tracks your personal transactions only — if an affiliated person repurchased the same asset within the window, you may need to consult a tax professional.

Q: How does partial proration work with my tax return?

A: You report only the allowed loss. If you had a $10,000 raw loss and the proration denied 50% ($5,000), you report a $5,000 capital loss on Schedule 3. The other $5,000 is invisibly embedded in your ACB.

Q: I sold at a loss but bought back on the same day — does the rule apply?

A: Yes. The day of sale is included in the 61-day window. A same-day repurchase is “within 30 days after” the sale (it’s 0 days after). If you still hold at day 30, the rule applies.

Q: What if I have superficial losses from a prior year?

A: They’re already embedded in your ACB. PrivateACB processes all transactions chronologically. Denied losses from 2023 increased your ACB in 2023, which carries forward to 2024 and beyond. There’s nothing extra to do.

Technical Details

For the full mathematical formulas — including the CRA proration formula with worked examples, detection conditions, edge cases (partial disposals, multiple repurchases, zero holdings), and verification procedures — see the Canadian ACB Formulas (Technical) guide.

Database Storage

PrivateACB stores superficial loss results in the superficial_losses table with a complete audit trail:

Loss details: disposal date, total loss, denied amount, ACB adjustment
CRA formula parameters: S (disposal quantity), P (repurchase quantity), B (owned at end), proration ratio
Window dates: 61-day window start and end dates
Links: references to the original disposal and repurchase transactions
Job ID: links to the calculation that generated the record

Canadian ACB Calculation — Step-by-step guide to running ACB calculations
Canadian ACB Formulas (Technical) — Mathematical formulas and detailed examples
Canadian Tax Reports — Schedule 3, T1135, ACB Summary, and Superficial Loss reports
US Wash Sale Rules — The comparable US rule (optional, different mechanics)
Data Viewer — Inspect superficial loss records in the database

CRA References

Section 54 of the Income Tax Act — Definition of “superficial loss”
Subsection 40(2)(g)(i) — Denial of superficial loss
Subsection 53(1)(f) — ACB increase for denied superficial loss
Income Tax Folio S3-F3-C1 — Replacement Property
Guide T4037 — Capital Gains (CRA)

Last Updated: February 2026 PrivateACB Version: 2.0 Jurisdiction: Canada only Tax Authority: Canada Revenue Agency (CRA)