Guatemala ISO: Q400,000 assets → Q1,000/quarter (1%)
The Impuesto de Solidaridad (ISO) is a quarterly tax on business activity in Guatemala, governed by Decree 73-2008. It is filed on form SAT-1608 through the SAT Declaraguate platform. Unlike ISR (which taxes profit) or IVA (which taxes sales), ISO taxes an asset- or income-based base using the larger of two calculations.
The taxable base is the larger of one quarter of opening net assets and one quarter of prior-year gross income. A 1% rate applies to that base. If net assets exceed four times gross income, only the income base is used. When the asset base is used, you subtract the IUSI already paid in the same quarter.
Default calculator example: net assets Q400,000 and income Q200,000 → asset base Q100,000 (larger) → ISO ≈ Q1,000.00 this quarter.
ISO formula (Decree 73-2008)
assetBase = netAssets ÷ 4
incomeBase = grossIncome ÷ 4
quarterlyISO = taxableBase × 1% (minus same-quarter IUSI when the asset base is used)
Asset vs. income rule (Art. 7)
| Condition | Base used | Example |
|---|---|---|
| Net assets > 4 × gross income | Income base only | Assets Q1,000,000, income Q200,000 → base Q50,000 → ISO Q500 |
| Asset base ≥ income base | Asset base | Assets Q400,000, income Q200,000 → base Q100,000 → ISO Q1,000 |
| Income base > asset base | Income base | Assets Q100,000, income Q800,000 → base Q200,000 → ISO Q2,000 |
Quick ISO scenario table
| Net assets | Gross income | Base used | Quarterly ISO |
|---|---|---|---|
| Q400,000 | Q200,000 | Assets Q100,000 | Q1,000.00 |
| Q100,000 | Q800,000 | Income Q200,000 | Q2,000.00 |
| Q1,000,000 | Q200,000 | Income only Q50,000 (Art. 7) | Q500.00 |
| Q800,000 | Q600,000 | Assets Q200,000 | Q2,000.00 |
| Q200,000 | Q200,000 | Tie Q50,000 | Q500.00 |
Worked examples
Default example (asset base)
- Net assets: Q400,000 → asset base = Q400,000 ÷ 4 = Q100,000
- Gross income: Q200,000 → income base = Q200,000 ÷ 4 = Q50,000
- Base used: Q100,000 (larger) → ISO ≈ Q1,000.00
- Gross margin (with Q180,000 cost of sales): (Q200,000 − Q180,000) ÷ Q200,000 = 10% → applies (margin > 4%)
Asset vs. income rule example (Art. 7)
- Net assets: Q1,000,000 (Q1,000,000 > Q200,000 × 4 = Q800,000)
- Use only the income base: Q200,000 ÷ 4 = Q50,000
- ISO ≈ Q500.00 (no IUSI is subtracted because the income base is used)
IUSI credit and short period
Article 9 of Decree 73-2008 lets you subtract the IUSI already paid in the same quarter, and only when the net-assets base is used. If your business starts or closes within a quarter (short period), the tax is prorated to the effective days. The ISO ↔ ISR credit of Article 11 is an adjustment handled in the annual filing, not the quarterly SAT-1608 payment: review it with your accountant.
| Case (assets Q400,000 / income Q200,000) | Quarter IUSI | Days | ISO due |
|---|---|---|---|
| No IUSI, full quarter | Q0 | 90 | Q1,000.00 |
| Q300 IUSI credit (asset base) | Q300 | 90 | Q700.00 |
| Short period 45 days | Q0 | 45 | Q500.00 |
| IUSI larger than gross ISO | Q5,000 | 90 | Q0.00 |
This calculator is an educational estimate of the Impuesto de Solidaridad (Decree 73-2008). It does not replace the SAT-1608 filing or tax advice. ISO mainly applies under the profitability and equity regimes with a gross margin above 4%. Always confirm your figures with an accountant or the SAT.
Related Guatemala calculators:
- Guatemala ISR calculator
- Compare ISR regimes
- Guatemala IUSI calculator
- SAT small taxpayer regime
- Guatemala IVA calculator
Official sources:
- SAT Guatemala — Solidarity Tax Law (Decree 73-2008)
- Congress of the Republic — Decree 73-2008
- SAT — Main taxes in Guatemala
- SAT — Declaraguate (form SAT-1608)
The Impuesto de Solidaridad (ISO) is a quarterly tax created by Decree 73-2008, paid by businesses in Guatemala through the Declaraguate platform on form SAT-1608. It is a 1% levy on the larger of one quarter of net assets and one quarter of gross income.
Compute an asset base (net assets ÷ 4) and an income base (gross income ÷ 4) and use the larger. If net assets exceed four times gross income, use only the income base. Apply 1% and, when the asset base is used, subtract IUSI already paid in the quarter.
ISO is filed and paid quarterly on form SAT-1608 through the SAT Declaraguate platform.
ISO mainly applies to taxpayers under the ISR profitability or business-income regimes and is associated with a gross margin above 4%. Check with the SAT or an accountant to confirm whether you are liable and under which regime.
Yes, but only when the net-assets base is used (Art. 9 of Decree 73-2008). You subtract the IUSI actually paid in the same quarter.
Yes. Article 11 of Decree 73-2008 lets you credit paid ISO against ISR. That adjustment is not part of the quarterly SAT-1608 estimate and is handled in the annual filing with your accountant.
The decree provides for a short period: if a business starts or ends operations within a quarter, tax is prorated to the effective days (base ÷ 90 × days).