Important
The examples presented in this documentation are for illustrative purposes only and serve as a suggestion for how to account for a credit reversal scenario.
The values used (dates, quantities, rates, and amounts) are generic examples and do not represent official parameters.
If the company’s real scenario contains particularities—such as different depreciation methods, internal reversal policies, or customized fields —, it is essential to adjust the formula according to operational reality and the applicable tax regulations.
To calculate the proportional amount of IBS/CBS credit reversal in cases of write-off, disposal, or loss of fixed assets, according to the criteria defined by Complementary Law LC 214/2025, art. 47, §§6º to 8º.
The calculation takes into account:
CTBVLTRIB(SN1->N1_IDTRIB,"IBSEST",,.T.)*SN4->N4_QUANTD*(1-((SN4->N4_DATA-SN1->N1_AQUISIC)/((100/SN3->N3_TXDEPR1)*365)))
Field / Function | Description |
CTBVLTRIB(SN1->N1_IDTRIB,"IBSEST",,.T.) | Returns the total value of the tax credit (IBS/CBS) recorded at the time of asset acquisition. |
N4_QUANTD | Represents the fractional percentage of the quantity written off (ex: 0,4 = 40%). |
N4_DATA | Date when the asset write-off was performed. |
SN1->N1_AQUISIC | Date of the asset acquisition in the system. |
SN3->N3_TXDEPR1 | Annual depreciation rate registered for the asset (in %). |
365 | Converts the annual rate into days for proportional calculation. |
The credit reversal consists of two proportions:
1 - Proportion of the quantity written off:
Represents the fraction of the asset being written off at that moment.
Example: N4_QUANTD = 0,4 → The asset is being written off at 40%.
2 - Proportion of the remaining credit:
Indicates how much of the credit has not yet been “consumed” through depreciation (useful life).
It is calculated as:
1 - (usage time / total useful life)
Thus, the older the asset, the smaller the remaining credit to be reversed.
1 - Determine the total credit amount of the asset:
CTBVLTRIB(SN1→N1_IDTRIB,"IBSEST",,.T.)
2 - Apply the write-off percentage:
Multiply the total credit by the fractional value in N4_QUANTD
(ex.: 40% = 0,4 → 40% of the credit).
3 - Apply the usage time factor (depreciation):
Calculate how much of the credit still “remains,” considering the asset’s useful life.
4 - Final result:
Data | Value |
Total credit amount IBS | R$ 1.000,00 |
The acquisition date. | 01/01/2023 |
Write-off Date | 01/01/2025 |
Rate of depreciation | 25% a.a. |
Posting-off Percentage (N4_QUANTD) | 0,4 (40%) |
Calculation:
1 - Total useful life:
100 ÷ 25 = 4 years = 1,460 days
2 - Time in use:
01/01/2025 − 01/01/2023 =730 days
3 - Remaining proportion:
1 − (730 ÷ 1460) = 0,5
4 - Applying the formula:
1,000 × 0.4 × 0.5 = 200
Reversal value = R$ 200.00
Practical interpretation
The idea is to calculate from right to left, respecting mathematical precedence:
1️⃣ Inner parentheses first
2️⃣ Multiplication and divisions
3️⃣ Subtractions and additions
Step 1 – Calculate the asset’s total useful life (in years, then in days)
Formula excerpt:
(100 / SN3->N3_TXDEPR1) * 365
Substituting:
(100 / 25) * 365
→ 4 × 365 = 1,460 days of total useful life
Step 2 – Calculate the asset’s use time (in days)
Formula excerpt:
N4_DATA - SN1->N1_AQUISIC
→ 2025-01-01 - 2023-01-01 = 730 days
Step 3 – Calculate the percentage of useful life already used
Formula excerpt:
((N4_DATA - SN1->N1_AQUISIC) / ((100 / SN3->N3_TXDEPR1) * 365))
Substituting:
730 / 1460 = 0,5
→ The asset has already used 50% of its useful life.
Step 4 – Calculate the remaining credit percentage
Formula excerpt:
1 - (previous result)
Substituting:
1 - 0,5 = 0,5
→ 50% of the credit remains (remaining proportion).
Step 5 – Apply the write-off percentage (quantity written off)
Formula excerpt:
N4_QUANTD * (previous result)
Substituting:
0,4 * 0,5 = 0,2
→ The total to be reversed equals 20% of the total credit.
Step 6 – Apply to the IBS credit value
Formula excerpt:
CTBVLTRIB(...) * (previous result)
Substituting:
1.000 * 0,2 = 200
Final reversal value = R$ 200,00
Summary of the sequence with calculation order
| Ordem | Operação | Resultado |
|---|---|---|
| 1 | (100 ÷ 25) × 365 | 1460 |
| 2 | 2025-01-01 − 2023-01-01 | 730 |
| 3 | 730 ÷ 1460 | 0.5 |
| 4 | 1 − 0,5 | 0.5 |
| 5 | 0,4 × 0,5 | 0.2 |
| 6 | 1.000 × 0,2 | 200,00 |
Practical interpretation
🔹 The asset has R$ 1,000 in credit.
🔹 You are writing off 40% of it.
🔹 The asset has used half of its useful life (2 of 4 years).
🔹 Therefore, 50% of the credit is still available.
🔹 40% × 50% = 20% of the total → R$ 200 reversal.