If you're running a Magento store and need to make the tax/VAT field unique like an email during registration, it's essential for compliance and preventing duplicate entries. This is especially important for VAT Registration in UAE, where businesses must ensure each VAT number is properly validated. Implementing a uniqueness check can help streamline tax compliance and avoid errors. Consider using custom validation or an extension to enforce uniqueness in the VAT field, ensuring a smoother registration process for businesses operating under UAE tax regulations.