Stress-free and efficient: tax.fish reliably takes care of your VAT returns, your tax registration in other European countries or your OSS reports throughout Europe and helps you to run your business in compliance with the law. Fast, efficient and simple. | Stress-free and efficient: tax.fish reliably takes care of your VAT returns, your tax registration in other European countries or your OSS reports throughout Europe and helps you to run your business in compliance with the law. Fast, economical and simple.