{
  "2025-01": {
    "userId": "user123",
    "month": "2025-01",
    "basicFee": 55000,
    "callFee": 12500,
    "dataFee": 8500,
    "smsFee": 2500,
    "roamingFee": 0,
    "discountFee": -5500,
    "totalFee": 72500,
    "paymentStatus": "PAID",
    "dueDate": "2025-01-25",
    "paymentDate": "2025-01-22",
    "plan": {
      "name": "5G 프리미엄",
      "basicFee": 55000,
      "dataLimit": "무제한"
    },
    "usage": {
      "callMinutes": 850,
      "dataGB": 25.6,
      "smsCount": 125
    }
  },
  "2025-02": {
    "userId": "user123", 
    "month": "2025-02",
    "basicFee": 55000,
    "callFee": 18200,
    "dataFee": 15000,
    "smsFee": 3200,
    "roamingFee": 45000,
    "discountFee": -8500,
    "totalFee": 127900,
    "paymentStatus": "PAID",
    "dueDate": "2025-02-25",
    "paymentDate": "2025-02-26",
    "plan": {
      "name": "5G 프리미엄",
      "basicFee": 55000,
      "dataLimit": "무제한"
    },
    "usage": {
      "callMinutes": 1240,
      "dataGB": 42.3,
      "smsCount": 160
    },
    "roamingUsage": {
      "country": "일본",
      "days": 5,
      "dataGB": 2.8
    }
  },
  "2025-03": {
    "userId": "user123",
    "month": "2025-03", 
    "basicFee": 55000,
    "callFee": 9800,
    "dataFee": 3200,
    "smsFee": 1800,
    "roamingFee": 0,
    "discountFee": -6500,
    "totalFee": 63300,
    "paymentStatus": "PAID",
    "dueDate": "2025-03-25",
    "paymentDate": "2025-03-20",
    "plan": {
      "name": "5G 프리미엄",
      "basicFee": 55000,
      "dataLimit": "무제한"
    },
    "usage": {
      "callMinutes": 670,
      "dataGB": 18.9,
      "smsCount": 90
    }
  },
  "2025-04": {
    "userId": "user123",
    "month": "2025-04",
    "basicFee": 55000,
    "callFee": 22400,
    "dataFee": 25000,
    "smsFee": 4500,
    "roamingFee": 0,
    "discountFee": -12000,
    "totalFee": 94900,
    "paymentStatus": "PAID", 
    "dueDate": "2025-04-25",
    "paymentDate": "2025-04-24",
    "plan": {
      "name": "5G 프리미엄",
      "basicFee": 55000,
      "dataLimit": "무제한"
    },
    "usage": {
      "callMinutes": 1520,
      "dataGB": 67.2,
      "smsCount": 225
    },
    "specialUsage": {
      "internationalCall": {
        "minutes": 45,
        "fee": 15000
      }
    }
  },
  "2025-05": {
    "userId": "user123",
    "month": "2025-05",
    "basicFee": 39000,
    "callFee": 8500,
    "dataFee": 18500,
    "smsFee": 1200,
    "roamingFee": 0,
    "discountFee": -3900,
    "totalFee": 63300,
    "paymentStatus": "PAID",
    "dueDate": "2025-05-25", 
    "paymentDate": "2025-05-23",
    "plan": {
      "name": "5G 스탠다드",
      "basicFee": 39000,
      "dataLimit": "100GB"
    },
    "usage": {
      "callMinutes": 580,
      "dataGB": 95.6,
      "smsCount": 60
    },
    "planChangeInfo": {
      "previousPlan": "5G 프리미엄",
      "changeDate": "2025-05-01",
      "reason": "요금절약"
    }
  },
  "2025-06": {
    "userId": "user123",
    "month": "2025-06",
    "basicFee": 39000,
    "callFee": 15600,
    "dataFee": 32000,
    "smsFee": 2800,
    "roamingFee": 125000,
    "discountFee": -7800,
    "totalFee": 206600,
    "paymentStatus": "OVERDUE",
    "dueDate": "2025-06-25",
    "paymentDate": null,
    "plan": {
      "name": "5G 스탠다드", 
      "basicFee": 39000,
      "dataLimit": "100GB"
    },
    "usage": {
      "callMinutes": 1060,
      "dataGB": 156.8,
      "smsCount": 140
    },
    "roamingUsage": {
      "country": "미국",
      "days": 10,
      "dataGB": 8.2,
      "callMinutes": 320
    },
    "overdueInfo": {
      "overdueAmount": 206600,
      "lateFee": 10000,
      "overdueDays": 15
    }
  },
  "2025-07": {
    "userId": "user123",
    "month": "2025-07",
    "basicFee": 39000,
    "callFee": 11200,
    "dataFee": 45000,
    "smsFee": 1500,
    "roamingFee": 0,
    "discountFee": -9500,
    "totalFee": 87200,
    "paymentStatus": "PAID",
    "dueDate": "2025-07-25",
    "paymentDate": "2025-07-10",
    "plan": {
      "name": "5G 스탠다드",
      "basicFee": 39000,
      "dataLimit": "100GB"
    },
    "usage": {
      "callMinutes": 760,
      "dataGB": 178.9,
      "smsCount": 75
    },
    "extraCharges": {
      "dataOverage": {
        "overGB": 78.9,
        "ratePerGB": 1000,
        "fee": 45000
      }
    }
  },
  "2025-08": {
    "userId": "user123",
    "month": "2025-08",
    "basicFee": 69000,
    "callFee": 9800,
    "dataFee": 0,
    "smsFee": 2200,
    "roamingFee": 0,
    "discountFee": -15000,
    "totalFee": 66000,
    "paymentStatus": "PAID",
    "dueDate": "2025-08-25",
    "paymentDate": "2025-08-20",
    "plan": {
      "name": "5G 플래티넘",
      "basicFee": 69000,
      "dataLimit": "무제한"
    },
    "usage": {
      "callMinutes": 670,
      "dataGB": 89.2,
      "smsCount": 110
    },
    "planChangeInfo": {
      "previousPlan": "5G 스탠다드", 
      "changeDate": "2025-08-01",
      "reason": "데이터 초과 방지"
    },
    "promotions": [
      {
        "name": "신규가입 할인",
        "discountAmount": 10000,
        "remainingMonths": 8
      }
    ]
  },
  "2025-09": {
    "userId": "user123",
    "month": "2025-09",
    "basicFee": 69000,
    "callFee": 25600,
    "dataFee": 0,
    "smsFee": 5200,
    "roamingFee": 78000,
    "discountFee": -13800,
    "totalFee": 164000,
    "paymentStatus": "PENDING",
    "dueDate": "2025-09-25",
    "paymentDate": null,
    "plan": {
      "name": "5G 플래티넘",
      "basicFee": 69000,
      "dataLimit": "무제한"
    },
    "usage": {
      "callMinutes": 1740,
      "dataGB": 124.7,
      "smsCount": 260
    },
    "roamingUsage": {
      "country": "유럽(독일, 프랑스)",
      "days": 14,
      "dataGB": 15.6,
      "callMinutes": 560
    }
  },
  "2025-10": {
    "userId": "user123", 
    "month": "2025-10",
    "basicFee": 69000,
    "callFee": 13400,
    "dataFee": 0,
    "smsFee": 1800,
    "roamingFee": 0,
    "discountFee": -8500,
    "totalFee": 75700,
    "paymentStatus": "PAID",
    "dueDate": "2025-10-25",
    "paymentDate": "2025-10-22",
    "plan": {
      "name": "5G 플래티넘", 
      "basicFee": 69000,
      "dataLimit": "무제한"
    },
    "usage": {
      "callMinutes": 910,
      "dataGB": 67.3,
      "smsCount": 90
    }
  },
  "2025-11": {
    "userId": "user123",
    "month": "2025-11",
    "basicFee": 69000,
    "callFee": 18900,
    "dataFee": 0,
    "smsFee": 3600,
    "roamingFee": 0,
    "discountFee": -12000,
    "totalFee": 79500,
    "paymentStatus": "PAID", 
    "dueDate": "2025-11-25",
    "paymentDate": "2025-11-18",
    "plan": {
      "name": "5G 플래티넘",
      "basicFee": 69000,
      "dataLimit": "무제한"
    },
    "usage": {
      "callMinutes": 1285,
      "dataGB": 145.8,
      "smsCount": 180
    },
    "specialEvents": [
      {
        "name": "블랙프라이데이 데이터 보너스",
        "bonusDataGB": 50,
        "validUntil": "2025-11-30"
      }
    ]
  },
  "2025-12": {
    "userId": "user123",
    "month": "2025-12",
    "basicFee": 69000,
    "callFee": 32500,
    "dataFee": 0,
    "smsFee": 6800,
    "roamingFee": 0,
    "discountFee": -18000,
    "totalFee": 90300,
    "paymentStatus": "CURRENT",
    "dueDate": "2025-12-25", 
    "paymentDate": null,
    "plan": {
      "name": "5G 플래티넘",
      "basicFee": 69000,
      "dataLimit": "무제한"
    },
    "usage": {
      "callMinutes": 2210,
      "dataGB": 198.4,
      "smsCount": 340
    },
    "yearEndSummary": {
      "totalPaidAmount": 1021900,
      "averageMonthlyBill": 93810,
      "totalDataUsageGB": 1312.7,
      "totalCallMinutes": 13497,
      "totalSmsCount": 1825,
      "planChanges": 3,
      "roamingCountries": ["일본", "미국", "독일", "프랑스"]
    }
  }
}