"We've been your client for 8 years. How did you miss this?"
A long-standing client, frustrated. Their accountant had spotted a discrepancy in the bank's tax report: a stock split hadn't been properly reflected.
It's a scenario that plays out in private banks across Europe every spring.
Here are the 5 most common tax reporting mistakes we see and what they really cost:
Mistake #1: One-size-fits-all reporting
Real impact: A Luxembourg bank sent the same report format to German and Belgian clients. Both groups called confused. Their accountants couldn't map the data to local tax forms.
Result: 120+ support calls in one month.
The fix: Jurisdiction-specific reports tailored to each country's requirements.
Mistake #2: Reactive delivery
Real impact: Clients request tax reports in March when filings are due in April. The bank scrambles. Quality suffers. Clients miss deadlines.
The fix: Automated delivery in January/February, before the rush.
Mistake #3: Incomplete transaction coverage
Real impact: A portfolio underwent a corporate spin-off. The bank's report didn't calculate the tax implications. The client's advisor spent €3,000 reconstructing the data. The client changed banks.
The fix: Systems that handle complex capital events, not just simple dividends.
Mistake #4: Black box calculations
Real impact: "Where does this number come from?" If you can't answer, you've lost credibility. One bank faced this question 200 times in a single tax season.
The fix: Transparent calculation documentation showing the source of every figure.
Mistake #5: Missing withholding tax documentation
Real impact: Without proof of foreign taxes paid, clients can't claim credits. They either pay double or spend months fighting with tax authorities.
The fix: Comprehensive foreign tax credit documentation in every report.
The bigger picture:
These aren't just operational issues. Each mistake erodes the trust that took years to build.
In an age where clients can move their assets with a few clicks, getting tax reporting right isn't optional - it's essential to retention.
What's the most challenging tax reporting issue you've faced?
