Reimbursement of Central Sales Tax: procedure for claims, documentation, and post audit controls for export oriented units. Appendix 6H prescribes the procedure for reimbursement of Central Sales Tax (CST) to EOUs, EHTP and STP units for CST actually paid on purchases used in production under the EOU scheme. Claims require a prescribed application, material receipt register entries, original invoices, proof of payment through banking channels, GST registration evidence, and a Chartered Accountant/Cost Accountant certificate verifying receipts and reconciliation with 'C' Forms where applicable. Reimbursement is quarterly, subject to filing timelines, post audit, random checks, eligibility criteria for certifiers, and recovery or penalty for irregular claims.