diff --git a/design/backend/api/participation-service-api.yaml b/design/backend/api/participation-service-api.yaml
index 6bf25d3..104e133 100644
--- a/design/backend/api/participation-service-api.yaml
+++ b/design/backend/api/participation-service-api.yaml
@@ -67,14 +67,14 @@ paths:
                 value:
                   eventId: "evt-12345-abcde"
                   name: "홍길동"
-                  phoneNumber: "010-1234-5678"
+                  phoneNumber: "01012345678"
                   entryPath: "SNS"
                   consentMarketing: true
               매장방문참여:
                 value:
                   eventId: "evt-12345-abcde"
                   name: "김철수"
-                  phoneNumber: "010-9876-5432"
+                  phoneNumber: "01098765432"
                   entryPath: "STORE_VISIT"
                   consentMarketing: false
       responses:
@@ -185,10 +185,10 @@ paths:
         - name: phone
           in: query
           required: false
-          description: 전화번호 검색 (부분 일치)
+          description: 전화번호 검색 (부분 일치, 숫자만)
           schema:
             type: string
-          example: "010-1234"
+          example: "01012"
         - name: page
           in: query
           required: false
@@ -422,9 +422,9 @@ components:
           example: "홍길동"
         phoneNumber:
           type: string
-          pattern: '^\d{3}-\d{4}-\d{4}$'
-          description: 전화번호 (하이픈 포함, 010-1234-5678 형식)
-          example: "010-1234-5678"
+          pattern: '^\d{10,11}$'
+          description: 전화번호 (숫자만, 10~11자리)
+          example: "01012345678"
         entryPath:
           type: string
           enum: