diff --git a/apps/as/src/pages/sewer-bsc-plan/ui/sections/biz-cst-matrix-form-section.tsx b/apps/as/src/pages/sewer-bsc-plan/ui/sections/biz-cst-matrix-form-section.tsx
index 710a81fcf..a5ebdae97 100644
--- a/apps/as/src/pages/sewer-bsc-plan/ui/sections/biz-cst-matrix-form-section.tsx
+++ b/apps/as/src/pages/sewer-bsc-plan/ui/sections/biz-cst-matrix-form-section.tsx
@@ -3,7 +3,7 @@
 import { useEffect, useMemo } from "react";
 import { useFormContext, useWatch } from "react-hook-form";
 
-import { NON_NEGATIVE_INPUT_PROPS, stripMinusSign } from "@/shared/lib";
+import { NON_NEGATIVE_INPUT_PROPS, sanitizeNumberInput } from "@/shared/lib";
 import { SectionCollapsible } from "@/shared/ui";
 import { Field } from "@/shared/ui/field";
 import { useAcntgSeMngTree } from "@/entities/acntg";
@@ -51,7 +51,7 @@ function BizCstMatrixFormSection() {
   ];
 
   function handleChange(acntgSeCd: string, planStpNo: number, value: string) {
-    const normalized = truncateDecimals(stripMinusSign(value), 3);
+    const normalized = truncateDecimals(sanitizeNumberInput(value), 3);
     const numValue = Number(normalized.replace(/,/g, "")) || 0;
     const next = recalculateBizCstMatrix(
       setAmt(getValues("bizCstList"), acntgSeCd, planStpNo, numValue),
diff --git a/apps/as/src/pages/sewer-bsc-plan/ui/sections/fnrs-cst-form-section.tsx b/apps/as/src/pages/sewer-bsc-plan/ui/sections/fnrs-cst-form-section.tsx
index 7ef5947f5..f4be7a396 100644
--- a/apps/as/src/pages/sewer-bsc-plan/ui/sections/fnrs-cst-form-section.tsx
+++ b/apps/as/src/pages/sewer-bsc-plan/ui/sections/fnrs-cst-form-section.tsx
@@ -3,7 +3,7 @@
 import { useMemo } from "react";
 import { useFormContext, useWatch } from "react-hook-form";
 
-import { NON_NEGATIVE_INPUT_PROPS, stripMinusSign } from "@/shared/lib";
+import { NON_NEGATIVE_INPUT_PROPS, sanitizeNumberInput } from "@/shared/lib";
 import { SectionCollapsible } from "@/shared/ui";
 import { Field } from "@/shared/ui/field";
 import { useAcntgSeMngTree } from "@/entities/acntg";
@@ -59,7 +59,7 @@ function FnrsCstFormSection() {
   );
 
   function handleChange(planStpNo: number, fieldKey: EditableFnrsKey, value: string) {
-    const numValue = Number(stripMinusSign(value).replace(/,/g, "")) || 0;
+    const numValue = Number(sanitizeNumberInput(value).replace(/,/g, "")) || 0;
     const draft = [...getValues("fnrsCstList")];
     const index = draft.findIndex((item) => item.planStpNo === planStpNo);
     if (index < 0) return;
diff --git a/apps/as/src/pages/sewer-bsc-plan/ui/sections/outline-form-section.tsx b/apps/as/src/pages/sewer-bsc-plan/ui/sections/outline-form-section.tsx
index 6375139a0..50bb4d629 100644
--- a/apps/as/src/pages/sewer-bsc-plan/ui/sections/outline-form-section.tsx
+++ b/apps/as/src/pages/sewer-bsc-plan/ui/sections/outline-form-section.tsx
@@ -4,7 +4,7 @@ import { useState } from "react";
 import { useFormContext, useWatch } from "react-hook-form";
 import dynamic from "next/dynamic";
 
-import { NON_NEGATIVE_INPUT_PROPS, stripMinusSign } from "@/shared/lib";
+import { NON_NEGATIVE_INPUT_PROPS, sanitizeNumberInput } from "@/shared/lib";
 import { SectionCollapsible } from "@/shared/ui";
 import { Field } from "@/shared/ui/field";
 import { truncateDecimals } from "@/widgets/pbadms-sprt";
@@ -62,8 +62,8 @@ function OutlineFormSection() {
     value: string,
     decimals?: number,
   ) {
-    const unsigned = stripMinusSign(value);
-    const normalized = decimals === undefined ? unsigned : truncateDecimals(unsigned, decimals);
+    const sanitized = sanitizeNumberInput(value);
+    const normalized = decimals === undefined ? sanitized : truncateDecimals(sanitized, decimals);
     const numValue = Number(normalized.replace(/,/g, "")) || 0;
     const draft = [...getValues("sewerBscPlanOtlnList")];
     const index = draft.findIndex((item) => item.planStpNo === planStpNo);
diff --git a/apps/as/src/pages/sewer-bsc-plan/ui/sections/tmplnt-form-section.tsx b/apps/as/src/pages/sewer-bsc-plan/ui/sections/tmplnt-form-section.tsx
index 8ee14fab2..bee7a8720 100644
--- a/apps/as/src/pages/sewer-bsc-plan/ui/sections/tmplnt-form-section.tsx
+++ b/apps/as/src/pages/sewer-bsc-plan/ui/sections/tmplnt-form-section.tsx
@@ -8,7 +8,7 @@ import { useConfirm } from "@frontend-opensource/use-react-hooks";
 import {
   getDefaultFileKey,
   NON_NEGATIVE_INPUT_PROPS,
-  stripMinusSign,
+  sanitizeNumberInput,
   useTus,
 } from "@/shared/lib";
 import { TextShimmer } from "@/shared/ui";
@@ -107,7 +107,7 @@ function TmplntDtlInput({ facilityIndex, planStpNo, fieldKey, decimals }: Tmplnt
             className="text-right"
             value={field.value ?? ""}
             onChange={(e) => {
-              const value = stripMinusSign(e.target.value.replace(/,/g, ""));
+              const value = sanitizeNumberInput(e.target.value.replace(/,/g, ""));
               const normalized = hasDecimals ? truncateDecimals(value, decimals) : value;
               field.onChange(Number(normalized) || 0);
             }}
diff --git a/apps/as/src/shared/lib/index.ts b/apps/as/src/shared/lib/index.ts
index b344b56bd..4735424af 100644
--- a/apps/as/src/shared/lib/index.ts
+++ b/apps/as/src/shared/lib/index.ts
@@ -2,7 +2,7 @@ export { getCookie, removeCookie, setCookie } from "./cookie";
 export { dayjs } from "./dayjs";
 export { getListHref, withListQs } from "./list-return-href";
 export { matchQueryStatus } from "./match-query-status";
-export { NON_NEGATIVE_INPUT_PROPS, stripMinusSign } from "./number-input";
+export { NON_NEGATIVE_INPUT_PROPS, sanitizeNumberInput } from "./number-input";
 export { queryClient } from "./query-client";
 export { useAlertStore } from "./use-alert-store";
 export { useDataTable } from "./use-data-table";
diff --git a/apps/as/src/shared/lib/number-input.ts b/apps/as/src/shared/lib/number-input.ts
index 228f6948b..ac65664b2 100644
--- a/apps/as/src/shared/lib/number-input.ts
+++ b/apps/as/src/shared/lib/number-input.ts
@@ -1,5 +1,7 @@
 import type { KeyboardEvent } from "react";
 
+const MAX_INTEGER_DIGITS = 10;
+
 function preventMinusKey(e: KeyboardEvent<HTMLInputElement>) {
   if (e.key === "-") e.preventDefault();
 }
@@ -7,7 +9,14 @@ function preventMinusKey(e: KeyboardEvent<HTMLInputElement>) {
 /** type="number" Input에 스프레드해 음수 입력(키·스피너)을 막는다 */
 export const NON_NEGATIVE_INPUT_PROPS = { min: 0, onKeyDown: preventMinusKey } as const;
 
-/** 붙여넣기 등으로 들어온 음수 부호를 제거한다 */
-export function stripMinusSign(value: string): string {
-  return value.replace(/-/g, "");
+/** 정수부를 maxDigits 자리까지 잘라낸다 (소수부는 유지) */
+function truncateIntegerDigits(value: string, maxDigits: number): string {
+  const dotIndex = value.indexOf(".");
+  if (dotIndex < 0) return value.slice(0, maxDigits);
+  return value.slice(0, Math.min(dotIndex, maxDigits)) + value.slice(dotIndex);
+}
+
+/** 숫자 입력 문자열에서 음수 부호를 제거하고 정수부를 최대 10자리로 제한한다 */
+export function sanitizeNumberInput(value: string): string {
+  return truncateIntegerDigits(value.replace(/-/g, ""), MAX_INTEGER_DIGITS);
 }
diff --git a/apps/as/src/widgets/pbadms-sprt/ui/business-cost-form-section.tsx b/apps/as/src/widgets/pbadms-sprt/ui/business-cost-form-section.tsx
index fb27309aa..8f32111c4 100644
--- a/apps/as/src/widgets/pbadms-sprt/ui/business-cost-form-section.tsx
+++ b/apps/as/src/widgets/pbadms-sprt/ui/business-cost-form-section.tsx
@@ -3,7 +3,7 @@
 import { useEffect, useMemo } from "react";
 import { useFormContext, useWatch } from "react-hook-form";
 
-import { NON_NEGATIVE_INPUT_PROPS, stripMinusSign } from "@/shared/lib";
+import { NON_NEGATIVE_INPUT_PROPS, sanitizeNumberInput } from "@/shared/lib";
 import { SectionCollapsible } from "@/shared/ui";
 import { Field } from "@/shared/ui/field";
 import { useAcntgSeMngTree } from "@/entities/acntg";
@@ -80,7 +80,7 @@ function BusinessCostFormSection() {
   }, [costItems, getValues, setValue]);
 
   function handleCostChange(index: number, fieldKey: CostFieldKey, value: string) {
-    const numValue = Number(truncateDecimals(stripMinusSign(value), COST_DECIMAL_PLACES)) || 0;
+    const numValue = Number(truncateDecimals(sanitizeNumberInput(value), COST_DECIMAL_PLACES)) || 0;
     const draft = [...getValues("bizCstList")];
     draft[index] = { ...draft[index], [fieldKey]: numValue };
     const next = recalculateBizCstTotals(draft, costItems);
diff --git a/apps/as/src/widgets/pbadms-sprt/ui/business-scale-form-section.tsx b/apps/as/src/widgets/pbadms-sprt/ui/business-scale-form-section.tsx
index c7342b670..88e4dba0b 100644
--- a/apps/as/src/widgets/pbadms-sprt/ui/business-scale-form-section.tsx
+++ b/apps/as/src/widgets/pbadms-sprt/ui/business-scale-form-section.tsx
@@ -3,7 +3,7 @@
 import { useEffect, useMemo } from "react";
 import { useFormContext, useWatch } from "react-hook-form";
 
-import { NON_NEGATIVE_INPUT_PROPS, stripMinusSign } from "@/shared/lib";
+import { NON_NEGATIVE_INPUT_PROPS, sanitizeNumberInput } from "@/shared/lib";
 import { SectionCollapsible } from "@/shared/ui";
 import { Field } from "@/shared/ui/field";
 import { useCnstpSeMngTree } from "@/entities/cnstp";
@@ -78,8 +78,8 @@ function BusinessScaleFormSection() {
 
   function handleScaleChange(index: number, fieldKey: ScaleFieldKey, value: string) {
     const item = scaleItems[index];
-    const unsigned = stripMinusSign(value);
-    const normalized = item?.numYn ? truncateDecimals(unsigned, item.dcptUnitCnt) : unsigned;
+    const sanitized = sanitizeNumberInput(value);
+    const normalized = item?.numYn ? truncateDecimals(sanitized, item.dcptUnitCnt) : sanitized;
     const numValue = Number(normalized) || 0;
     const draft = [...getValues("bzScaleList")];
     draft[index] = { ...draft[index], [fieldKey]: numValue };
@@ -101,6 +101,7 @@ function BusinessScaleFormSection() {
   return (
     <SectionCollapsible title="사업규모">
       <div className="overflow-x-auto">
+        <p className="mb-2 text-right font-normal text-muted-foreground">(단위: 백만원)</p>
         <Table variant="secondary">
           <colgroup>
             <col width="20%" />
diff --git a/apps/as/src/widgets/pbadms-sprt/ui/fnrs-shar-form-section.tsx b/apps/as/src/widgets/pbadms-sprt/ui/fnrs-shar-form-section.tsx
index 9604ac7fc..68a5019fa 100644
--- a/apps/as/src/widgets/pbadms-sprt/ui/fnrs-shar-form-section.tsx
+++ b/apps/as/src/widgets/pbadms-sprt/ui/fnrs-shar-form-section.tsx
@@ -6,7 +6,7 @@ import { useFormContext, useWatch } from "react-hook-form";
 import {
   getDefaultFileKey,
   NON_NEGATIVE_INPUT_PROPS,
-  stripMinusSign,
+  sanitizeNumberInput,
   useTus,
 } from "@/shared/lib";
 import { AttachmentFileField, SectionCollapsible } from "@/shared/ui";
@@ -147,7 +147,7 @@ function FnrsSharFormSection({ initialSharTree, initialSharAtchFiles }: FnrsShar
     if (fieldKey === "rmrkCn") {
       draft[index] = { ...row, rmrkCn: value };
     } else {
-      const numValue = Number(stripMinusSign(value)) || 0;
+      const numValue = Number(sanitizeNumberInput(value)) || 0;
       draft[index] = { ...row, [fieldKey]: numValue };
     }