Monotributo Tax Evasion Fraudulent Activities Legal Obligations Filing Deadlines Tax Fraud Legal Consequences Tax Enforcement Tax Investigations Monotributista Requirements Taxpayer Data Management Invoicing Systems Regularization Programs Electronic Transactions IRS Enforcement Actions Document Verification Fraud Prevention Euskara Language Payment Plans Penalties Taxpayer Obligations Deadline Extensions Document Requirements Tax Deductions Constancia de Situación Fiscal Taxpayer Responsibilities Legal Settlements Tax Audit Tax Evasion Cases E-filing Tax Overpayment Fiscal Regularization International Tax Issues Adjustment for Inflation Fiscal Obligations Recategorización Process Shell Companies HMRC Online Services Tax Audit Reports IGV Fiscal Measures Audit Requirements Tax Planning Tax Practitioners International Tax Reporting Regulatory Issues Digital Tax Reporting Tax Authority Fraudulent Practices Tax Issues Tax Disputes Tax Classification