diff --git a/src/main/java/com/acquirex/approval/service/CardAcquisitionApprovalService.java b/src/main/java/com/acquirex/approval/service/CardAcquisitionApprovalService.java
new file mode 100644
index 0000000..c2e4bb2
--- /dev/null
+++ b/src/main/java/com/acquirex/approval/service/CardAcquisitionApprovalService.java
@@ -0,0 +1,118 @@
+package com.acquirex.approval.service;
+
+import com.acquirex.approval.domain.ApprovalStatus;
+import com.acquirex.approval.domain.CardAcquisitionApproval;
+import com.acquirex.approval.dto.ApprovalRequest;
+import com.acquirex.approval.dto.ApprovalResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+import java.math.BigDecimal;
+import java.time.LocalDateTime;
+import java.util.UUID;
+
+/**
+ * Service for card acquisition approval processing.
+ * Migrated to Spring Boot 3 with Jakarta EE 9+ compatibility.
+ */
+@Service
+public class CardAcquisitionApprovalService {
+
+    private static final Logger log = LoggerFactory.getLogger(CardAcquisitionApprovalService.class);
+    private static final BigDecimal MAX_APPROVAL_AMOUNT = new BigDecimal("1000000.00");
+    private static final BigDecimal HIGH_RISK_THRESHOLD = new BigDecimal("500000.00");
+
+    /**
+     * Process a card acquisition approval request.
+     * @param request the approval request
+     * @return the approval response
+     */
+    public ApprovalResponse processApproval(ApprovalRequest request) {
+        log.info("Processing approval request: {}", request.getRequestId());
+        validateRequest(request);
+        ApprovalStatus status = determineApprovalStatus(request.getAmount());
+        String approvedBy = determineApprover(status);
+        CardAcquisitionApproval approval = createApproval(request, status, approvedBy);
+        log.info("Approval processed: requestId={}, status={}, amount={}",
+                request.getRequestId(), status, request.getAmount());
+        return buildResponse(approval, status);
+    }
+
+    /**
+     * Validate the approval request.
+     * @param request the request to validate
+     * @throws IllegalArgumentException if validation fails
+     */
+    void validateRequest(ApprovalRequest request) {
+        if (request.getCardNumber() == null || request.getCardNumber().length() < 13) {
+            throw new IllegalArgumentException("Invalid card number format");
+        }
+        if (request.getMerchantId() == null || request.getMerchantId().isBlank()) {
+            throw new IllegalArgumentException("Merchant ID is required");
+        }
+    }
+
+    /**
+     * Determine approval status based on amount.
+     * @param amount the transaction amount
+     * @return the determined status
+     */
+    ApprovalStatus determineApprovalStatus(BigDecimal amount) {
+        if (amount.compareTo(MAX_APPROVAL_AMOUNT) > 0) return ApprovalStatus.REJECTED;
+        if (amount.compareTo(HIGH_RISK_THRESHOLD) > 0) return ApprovalStatus.PENDING;
+        return ApprovalStatus.APPROVED;
+    }
+
+    /**
+     * Determine the approver based on status.
+     * @param status the approval status
+     * @return the approver identifier
+     */
+    String determineApprover(ApprovalStatus status) {
+        return switch (status) {
+            case APPROVED, REJECTED -> "SYSTEM";
+            case PENDING -> "MANUAL_REVIEW";
+            case CANCELLED -> "CANCELLED";
+        };
+    }
+
+    /**
+     * Create the approval record.
+     */
+    CardAcquisitionApproval createApproval(ApprovalRequest request, ApprovalStatus status, String approvedBy) {
+        LocalDateTime now = LocalDateTime.now();
+        return new CardAcquisitionApproval(
+                generateId(), request.getRequestId(), maskCardNumber(request.getCardNumber()),
+                request.getMerchantId(), request.getAmount(), status, now, now, approvedBy);
+    }
+
+    /**
+     * Build the approval response.
+     */
+    ApprovalResponse buildResponse(CardAcquisitionApproval approval, ApprovalStatus status) {
+        String message = switch (status) {
+            case APPROVED -> "Card acquisition approved successfully";
+            case REJECTED -> "Card acquisition rejected: amount exceeds limit";
+            case PENDING -> "Card acquisition pending manual review";
+            case CANCELLED -> "Card acquisition cancelled";
+        };
+        return new ApprovalResponse(approval.getId(), approval.getRequestId(), status,
+                approval.getAmount(), approval.getUpdatedAt(), message);
+    }
+
+    /**
+     * Mask card number for logging/security.
+     */
+    String maskCardNumber(String cardNumber) {
+        if (cardNumber == null || cardNumber.length() < 4) return "****";
+        return "****-****-****-" + cardNumber.substring(cardNumber.length() - 4);
+    }
+
+    /**
+     * Generate unique ID for approval records.
+     */
+    Long generateId() {
+        return UUID.randomUUID().getMostSignificantBits() & Long.MAX_VALUE;
+    }
+}
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