diff --git a/src/pages/CustomerDetailPage/CustomerDetailPage.tsx b/src/pages/CustomerDetailPage/CustomerDetailPage.tsx
index ed2551f..b20c056 100644
--- a/src/pages/CustomerDetailPage/CustomerDetailPage.tsx
+++ b/src/pages/CustomerDetailPage/CustomerDetailPage.tsx
@@ -174,27 +174,40 @@ function CustomerDetailPage() {
   const handleSaveEdit = async () => {
     if (!editedCustomer) return;
 
-    const requestData = {
-      name: editedCustomer.name,
-      phoneNo: editedCustomer.phoneNo,
-      telProvider: editedCustomer.telProvider,
-      legalDistrictCode: editedCustomer.legalDistrictCode,
-      minRent: editedCustomer.minRent,
-      maxRent: editedCustomer.maxRent,
-      trafficSource: editedCustomer.trafficSource || null,
-      landlord: editedCustomer.landlord,
-      tenant: editedCustomer.tenant,
-      buyer: editedCustomer.buyer,
-      seller: editedCustomer.seller,
-      maxPrice: editedCustomer.maxPrice,
-      minPrice: editedCustomer.minPrice,
-      minDeposit: editedCustomer.minDeposit,
-      maxDeposit: editedCustomer.maxDeposit,
-      birthday: editedCustomer.birthDay,
-      labelUids: editedCustomer.labels.map((label) => label.uid),
-    };
-
     try {
+      if (!editedCustomer.name) {
+        toast.error("이름을 입력해주세요.");
+        return;
+      }
+      if (!editedCustomer.phoneNo) {
+        toast.error("전화번호를 입력해주세요.");
+        return;
+      }
+      if (editedCustomer.birthDay && !/^\d{8}$/.test(editedCustomer.birthDay)) {
+        toast.error("생년월일을 올바르게 입력해주세요. ex)19910501");
+        return;
+      }
+
+      const requestData = {
+        name: editedCustomer.name,
+        phoneNo: editedCustomer.phoneNo,
+        telProvider: editedCustomer.telProvider,
+        legalDistrictCode: editedCustomer.legalDistrictCode,
+        minRent: editedCustomer.minRent,
+        maxRent: editedCustomer.maxRent,
+        trafficSource: editedCustomer.trafficSource || null,
+        landlord: editedCustomer.landlord,
+        tenant: editedCustomer.tenant,
+        buyer: editedCustomer.buyer,
+        seller: editedCustomer.seller,
+        maxPrice: editedCustomer.maxPrice,
+        minPrice: editedCustomer.minPrice,
+        minDeposit: editedCustomer.minDeposit,
+        maxDeposit: editedCustomer.maxDeposit,
+        birthday: editedCustomer.birthDay,
+        labelUids: editedCustomer.labels.map((label) => label.uid),
+      };
+
       const response = await apiClient.put(
         `/customers/${customerId}`,
         requestData
@@ -205,9 +218,9 @@ function CustomerDetailPage() {
         setIsEditing(false);
         fetchCustomerData();
       }
-    } catch (error) {
+    } catch (error: any) {
       console.error("Failed to update customer:", error);
-      toast.error("고객 정보 수정에 실패했습니다.");
+      toast.error(error.response?.data?.message || "고객 정보 수정에 실패했습니다.");
     }
   };
 
diff --git a/src/pages/CustomerListPage/CustomerAddButtonList/CustomerAddModal/CustomerAddModal.tsx b/src/pages/CustomerListPage/CustomerAddButtonList/CustomerAddModal/CustomerAddModal.tsx
index 39124ab..05e1969 100644
--- a/src/pages/CustomerListPage/CustomerAddButtonList/CustomerAddModal/CustomerAddModal.tsx
+++ b/src/pages/CustomerListPage/CustomerAddButtonList/CustomerAddModal/CustomerAddModal.tsx
@@ -22,6 +22,7 @@ import Button from "@components/Button";
 import TextField from "@components/TextField";
 import apiClient from "@apis/apiClient";
 import AddIcon from '@mui/icons-material/Add';
+import { toast } from "react-toastify";
 
 const phoneRegex = /^\d{3}-\d{3,4}-\d{4}$/;
 
@@ -116,10 +117,31 @@ function CustomerAddModal({
 
   const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
     const { name, value, type, checked } = e.target;
-    setFormData(prev => ({
-      ...prev,
-      [name]: type === 'checkbox' ? checked : value
-    }));
+    
+    if (name === 'phoneNo') {
+      // 숫자만 추출
+      const numbers = value.replace(/[^0-9]/g, '');
+      
+      // 전화번호 형식으로 변환
+      let formattedNumber = '';
+      if (numbers.length <= 3) {
+        formattedNumber = numbers;
+      } else if (numbers.length <= 7) {
+        formattedNumber = `${numbers.slice(0, 3)}-${numbers.slice(3)}`;
+      } else {
+        formattedNumber = `${numbers.slice(0, 3)}-${numbers.slice(3, 7)}-${numbers.slice(7, 11)}`;
+      }
+      
+      setFormData(prev => ({
+        ...prev,
+        [name]: formattedNumber
+      }));
+    } else {
+      setFormData(prev => ({
+        ...prev,
+        [name]: type === 'checkbox' ? checked : value
+      }));
+    }
   };
 
   const handleRegionChange = (type: 'sido' | 'sigungu' | 'dong') => (event: SelectChangeEvent) => {
@@ -138,6 +160,19 @@ function CustomerAddModal({
 
   const handleSubmit = async () => {
     try {
+      if (!formData.name) {
+        toast.error("이름을 입력해주세요.");
+        return;
+      }
+      if (!formData.phoneNo) {
+        toast.error("전화번호를 입력해주세요.");
+        return;
+      }
+      if (formData.birthDay && !/^\d{8}$/.test(formData.birthDay)) {
+        toast.error("생년월일을 올바르게 입력해주세요. ex)19910501");
+        return;
+      }
+
       // 선택된 지역 코드 (동 > 군구 > 시도 순으로 선택)
       const selectedRegion = region.selectedDong || region.selectedSigungu || region.selectedSido;
 
@@ -171,11 +206,13 @@ function CustomerAddModal({
       const response = await apiClient.post("/customers", customerData);
 
       if (response.status === 201) {
-        fetchCustomerList();  // 목록 새로고침
-        onClose();           // 모달 닫기
+        toast.success("고객 등록에 성공했습니다.");
+        fetchCustomerList();  
+        onClose();     
       }
-    } catch (error) {
-      console.error("고객 등록 실패:", error);
+    } catch (error: any) {
+      console.error("Failed to register customer:", error);
+      toast.error(error.response?.data?.message || "고객 등록 실패");
     }
   };
 
@@ -700,7 +737,7 @@ function CustomerAddModal({
           onClick={handleSubmit}
           variant="contained"
           sx={{ bgcolor: '#6366F1' }}
-          disabled={isSubmitButtonDisabled}
+          disabled={false}
         />
       </DialogActions>
     </Dialog>