Solidarity Tax (ISO) in Guatemala (2026)

The Impuesto de Solidaridad (ISO) is Guatemala’s minimum business tax, designed to ensure that larger businesses always contribute to the tax system regardless of whether they report profits. It applies to businesses and individuals with economic activity whose net assets or gross annual income exceeds Q3 million (approximately $390,000 USD).

The mechanics are straightforward: every quarter, you pay 1% of the greater of one-quarter of your net assets or one-quarter of your gross income. The critical feature of the ISO is its cross-crediting relationship with ISR — you can credit ISO paid against your ISR liability, and vice versa. This means the ISO effectively functions as a floor: if your ISR is low (because of high deductions or losses), the ISO ensures a minimum tax payment. If your ISR is already substantial, the ISO credit offsets it.

For pequenos contribuyentes and businesses under Q3 million in both assets and income, the ISO does not apply. It is primarily a concern for established medium and large businesses.

Quick summary: Quarterly tax of 1% on the greater of net assets or gross income (quarterly portion). Applies to businesses with assets or income above Q3 million. Filed on Declaraguate. Creditable against ISR and vice versa.

Information verified March 2026.

Tax Rate and Base

Who Pays ISO

• Businesses (personas juridicas) with net assets or gross income > Q3 million
• Individuals with economic activity meeting the same thresholds
• Both ISR regimes — whether you are on utilidades (25%) or optional simplified (5-7%)

Who Is Exempt:

• Businesses and individuals with BOTH net assets AND income below Q3 million
• Pequenos contribuyentes
• Newly inscribed businesses (first 4 quarters)
• Non-profit organizations with authorized exempt status
• Universities and educational institutions
• Diplomatic missions and international organizations
• Cooperatives (certain conditions)

Quarterly Calendar

Step-by-Step Process

1. Determine your tax base — compare 1/4 of your net assets to 1/4 of your gross annual income. Use the GREATER value.
2. Calculate ISO: 1% of that quarterly base
3. Go to declaraguate.sat.gob.gt
4. Log in and select the ISO quarterly form
5. Enter financial data — assets and income for the period
6. Review calculated ISO
7. Apply any ISR credit (if you have ISR overpayments to credit against ISO)
8. Validate and freeze the form
9. Generate payment voucher and pay within 10 business days of quarter end

ISO Calculation Example

A business with Q5 million in net assets and Q8 million in gross annual income:

1/4 of net assets:    Q1,250,000
1/4 of gross income:  Q2,000,000
Base (greater of two): Q2,000,000
ISO (1%):              Q20,000 per quarter

Annual ISO: Q80,000 (Q20,000 x 4 quarters)

Cross-Crediting: ISO vs. ISR

This is the most important concept to understand about ISO:

Option A: Credit ISO against ISR

• You pay ISO quarterly
• At year-end (or quarterly for simplified ISR), you credit the ISO paid against your ISR liability
• If ISR > ISO: you only pay the difference as ISR
• Result: total tax = ISR only (ISO was fully credited)

Option B: Credit ISR against ISO

• You pay ISR (quarterly or annual)
• You credit the ISR paid against your quarterly ISO
• If ISO > ISR: you only pay the difference as ISO
• Result: total tax = ISO only (ISR was fully credited)

In practice, your accountant determines which approach results in lower total taxes. The key principle: you should NEVER pay both the full ISO AND the full ISR — the credit mechanism prevents double taxation.

From the US (Diaspora Info)

• If you own a business in Guatemala with assets or income above Q3 million, ISO applies regardless of where you live
• Your Guatemalan accountant handles this — ISO calculation requires financial statements and should be managed alongside your ISR
• Declaraguate works remotely — filing can be done from the US
• Real estate — if you own significant property in Guatemala, the net asset value may push you above the Q3 million threshold
• Cross-crediting strategy — ensure your accountant optimizes the ISO/ISR credit to minimize total tax

Tips & Common Mistakes

1. Track the cross-credit carefully. The ISO-ISR credit is the most commonly mismanaged element. Your accountant should maintain a running balance of ISO paid and ISR credits applied. Errors result in overpayment or SAT penalties.

2. New businesses get 4 quarters free. If you just registered your business, you are exempt from ISO for the first 4 calendar quarters. Make sure your accountant applies this exemption correctly.

3. Use the higher base, not the lower. The law says the base is the GREATER of net assets or gross income. Accidentally using the lower figure constitutes underpayment, which triggers penalties and interest.

4. Q3 million threshold is checked annually. Review your numbers each year. If your business grows past Q3 million in assets or income, ISO kicks in for the following year’s quarterly filings.

5. File even if exempt. If you are on the border of the Q3 million threshold, it may be prudent to file zero ISO declarations to demonstrate good faith to SAT, rather than simply not filing and hoping they do not notice.

Official Links

• Declaraguate
• SAT — Agencia Virtual
• SAT Call Center: 1544