diff --git a/B09_Estimation/B09_Estimation_Router.py b/B09_Estimation/B09_Estimation_Router.py
index ed33fc40..9be99af8 100644
--- a/B09_Estimation/B09_Estimation_Router.py
+++ b/B09_Estimation/B09_Estimation_Router.py
@@ -755,8 +755,10 @@ async def get_bill(project_id: UUID) -> JSONResponse:
     """
     from B08_Quantity.B08_Quantity_Router_Material import get_handoff, structure_bill_prices
 
-    build = cached_build()
     try:
+        # ⚠ **그 프로젝트가 고른 값**으로 조립한 단가표 — 구조물도 미리보기(`_build_for`)와 한 벌.
+        #   기본값(`cached_build()`)을 쓰면 계수를 고른 프로젝트에서 화면과 내역이 갈림(브레인).
+        build = await _build_for(project_id)
         response = await get_handoff(project_id)
         payload = json.loads(bytes(response.body).decode("utf-8"))
     except Exception:
@@ -811,7 +813,8 @@ async def get_price_basis_detail(project_id: UUID, code: str) -> JSONResponse:
     from B09_Estimation.B09_Estimation_PriceBasis import price_basis_detail
 
     try:
-        body = price_basis_detail(code)
+        # 내역서와 같은 단가표 — 번호·금액이 내역 줄과 갈리지 않게.
+        body = price_basis_detail(code, await _build_for(project_id))
     except Exception:
         logger.exception("B09 단가산출서 조회 실패: project_id=%s, code=%s", project_id, code)
         return JSONResponse(