diff --git a/frontend/app/(main)/COMPANY_10/sales/order/page.tsx b/frontend/app/(main)/COMPANY_10/sales/order/page.tsx
index 1cb49efb..949e7e79 100644
--- a/frontend/app/(main)/COMPANY_10/sales/order/page.tsx
+++ b/frontend/app/(main)/COMPANY_10/sales/order/page.tsx
@@ -1104,7 +1104,16 @@ export default function SalesOrderPage() {
                 </div>
                 <div className="space-y-1">
                   <Label className="text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">입력방식</Label>
-                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => setMasterForm((p) => ({ ...p, input_mode: v }))}>
+                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => {
+                    setMasterForm((p) => {
+                      const next = { ...p, input_mode: v };
+                      delete next.partner_id;
+                      delete next.delivery_partner_id;
+                      delete next.delivery_address;
+                      return next;
+                    });
+                    setDeliveryOptions([]);
+                  }}>
                     <SelectTrigger className="h-9"><SelectValue placeholder="선택" /></SelectTrigger>
                     <SelectContent>
                       {(categoryOptions["input_mode"] || []).map((o) => (
diff --git a/frontend/app/(main)/COMPANY_16/sales/order/page.tsx b/frontend/app/(main)/COMPANY_16/sales/order/page.tsx
index 1cb49efb..949e7e79 100644
--- a/frontend/app/(main)/COMPANY_16/sales/order/page.tsx
+++ b/frontend/app/(main)/COMPANY_16/sales/order/page.tsx
@@ -1104,7 +1104,16 @@ export default function SalesOrderPage() {
                 </div>
                 <div className="space-y-1">
                   <Label className="text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">입력방식</Label>
-                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => setMasterForm((p) => ({ ...p, input_mode: v }))}>
+                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => {
+                    setMasterForm((p) => {
+                      const next = { ...p, input_mode: v };
+                      delete next.partner_id;
+                      delete next.delivery_partner_id;
+                      delete next.delivery_address;
+                      return next;
+                    });
+                    setDeliveryOptions([]);
+                  }}>
                     <SelectTrigger className="h-9"><SelectValue placeholder="선택" /></SelectTrigger>
                     <SelectContent>
                       {(categoryOptions["input_mode"] || []).map((o) => (
diff --git a/frontend/app/(main)/COMPANY_29/sales/order/page.tsx b/frontend/app/(main)/COMPANY_29/sales/order/page.tsx
index 1cb49efb..949e7e79 100644
--- a/frontend/app/(main)/COMPANY_29/sales/order/page.tsx
+++ b/frontend/app/(main)/COMPANY_29/sales/order/page.tsx
@@ -1104,7 +1104,16 @@ export default function SalesOrderPage() {
                 </div>
                 <div className="space-y-1">
                   <Label className="text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">입력방식</Label>
-                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => setMasterForm((p) => ({ ...p, input_mode: v }))}>
+                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => {
+                    setMasterForm((p) => {
+                      const next = { ...p, input_mode: v };
+                      delete next.partner_id;
+                      delete next.delivery_partner_id;
+                      delete next.delivery_address;
+                      return next;
+                    });
+                    setDeliveryOptions([]);
+                  }}>
                     <SelectTrigger className="h-9"><SelectValue placeholder="선택" /></SelectTrigger>
                     <SelectContent>
                       {(categoryOptions["input_mode"] || []).map((o) => (
diff --git a/frontend/app/(main)/COMPANY_7/sales/order/page.tsx b/frontend/app/(main)/COMPANY_7/sales/order/page.tsx
index 984e359c..81211602 100644
--- a/frontend/app/(main)/COMPANY_7/sales/order/page.tsx
+++ b/frontend/app/(main)/COMPANY_7/sales/order/page.tsx
@@ -1104,7 +1104,17 @@ export default function SalesOrderPage() {
                 </div>
                 <div className="space-y-1">
                   <Label className="text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">입력방식</Label>
-                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => setMasterForm((p) => ({ ...p, input_mode: v }))}>
+                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => {
+                    setMasterForm((p) => {
+                      const next = { ...p, input_mode: v };
+                      // 입력방식 변경 시 거래처 관련 값 초기화
+                      delete next.partner_id;
+                      delete next.delivery_partner_id;
+                      delete next.delivery_address;
+                      return next;
+                    });
+                    setDeliveryOptions([]);
+                  }}>
                     <SelectTrigger className="h-9"><SelectValue placeholder="선택" /></SelectTrigger>
                     <SelectContent>
                       {(categoryOptions["input_mode"] || []).map((o) => (
diff --git a/frontend/app/(main)/COMPANY_8/sales/order/page.tsx b/frontend/app/(main)/COMPANY_8/sales/order/page.tsx
index 1cb49efb..949e7e79 100644
--- a/frontend/app/(main)/COMPANY_8/sales/order/page.tsx
+++ b/frontend/app/(main)/COMPANY_8/sales/order/page.tsx
@@ -1104,7 +1104,16 @@ export default function SalesOrderPage() {
                 </div>
                 <div className="space-y-1">
                   <Label className="text-[11px] font-semibold uppercase tracking-wide text-muted-foreground">입력방식</Label>
-                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => setMasterForm((p) => ({ ...p, input_mode: v }))}>
+                  <Select value={masterForm.input_mode || ""} onValueChange={(v) => {
+                    setMasterForm((p) => {
+                      const next = { ...p, input_mode: v };
+                      delete next.partner_id;
+                      delete next.delivery_partner_id;
+                      delete next.delivery_address;
+                      return next;
+                    });
+                    setDeliveryOptions([]);
+                  }}>
                     <SelectTrigger className="h-9"><SelectValue placeholder="선택" /></SelectTrigger>
                     <SelectContent>
                       {(categoryOptions["input_mode"] || []).map((o) => (