If a person is uncertain about their zakat calculation, especially with complex finances, here are steps they can take to fulfill their obligation correctly:

1. Consult a Knowledgeable Scholar or Islamic Financial Advisor: An expert in Islamic finance can guide you on calculating zakat accurately based on your specific assets, liabilities, and income. Scholars trained in fiqh (Islamic jurisprudence) or Islamic financial advisors can help clarify which assets are zakatable and how to assess their value.
2. Use Reliable Zakat Calculators: Several reputable Islamic organizations and financial institutions offer online zakat calculators. However, for complex financial situations, such calculators are just a starting point, and personalized guidance may still be necessary.
3. Document and Review Assets and Liabilities: Keep a clear record of all zakatable assets (such as cash, gold, investments, and trade goods) and liabilities (debts owed to others). Reviewing this information annually can help ensure accuracy and avoid overlooking any zakatable items.
4. Estimate Conservatively if in Doubt: If there’s still some uncertainty, it’s generally advisable to estimate conservatively. This ensures that you meet the obligation fully, potentially giving slightly more if needed.
5. Seek Long-term Guidance: If your financial situation is consistently complex, you might consider developing a relationship with an Islamic financial advisor who can guide you annually or whenever significant financial changes occur.
6. Make Dua and Intend Sincerity: Islam emphasizes intention (niyyah). If you’ve made an honest effort to calculate zakat accurately, trust that Allah will accept it. Making dua for forgiveness and correctness in your calculation is also encouraged.