diff --git a/internal/httpapi/handlers.go b/internal/httpapi/handlers.go
index e85ed67..8609465 100644
--- a/internal/httpapi/handlers.go
+++ b/internal/httpapi/handlers.go
@@ -45,6 +45,7 @@ var navItems = []NavItem{
 	{Key: "approvals", Label: "승인 관리", Path: "/admin/approvals", Icon: "CheckSquare", AdminOnly: true, Section: "관리자"},
 	{Key: "attendance-admin", Label: "근무 관리", Path: "/admin/attendance", Icon: "ClipboardList", AdminOnly: true, Section: "관리자"},
 	{Key: "projects-admin", Label: "프로젝트 관리", Path: "/admin/projects", Icon: "FolderCog", AdminOnly: true, Section: "관리자"},
+	{Key: "master", Label: "기준정보", Path: "/admin/master", Icon: "Database", AdminOnly: true, Section: "관리자"},
 	{Key: "incentive-admin", Label: "인센티브 관리", Path: "/admin/incentive", Icon: "Calculator", AdminOnly: true, Section: "관리자"},
 	{Key: "accounting", Label: "회계", Path: "/admin/accounting", Icon: "Wallet", AdminOnly: true, Section: "관리자"},
 	{Key: "members", Label: "구성원", Path: "/admin/members", Icon: "Users", AdminOnly: true, Section: "관리자"},
diff --git a/internal/httpapi/handlers_accounting.go b/internal/httpapi/handlers_accounting.go
index 96e3927..3083204 100644
--- a/internal/httpapi/handlers_accounting.go
+++ b/internal/httpapi/handlers_accounting.go
@@ -141,6 +141,14 @@ func (s *Server) handlePatchTax(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, t)
 }
 
+func (s *Server) handleDeleteTax(w http.ResponseWriter, r *http.Request) {
+	if !s.requireAdmin(w, r) {
+		return
+	}
+	s.db.Delete(&models.TaxRecord{}, "id = ?", chi.URLParam(r, "taxId"))
+	writeJSON(w, http.StatusOK, map[string]bool{"ok": true})
+}
+
 // ---- summary: cashflow vs incentive gap -----------------------------------
 
 type acctSummary struct {
diff --git a/internal/httpapi/handlers_projects.go b/internal/httpapi/handlers_projects.go
index ba72710..b2e9834 100644
--- a/internal/httpapi/handlers_projects.go
+++ b/internal/httpapi/handlers_projects.go
@@ -78,6 +78,60 @@ func (s *Server) handleCreateVersion(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusCreated, v)
 }
 
+// patchByID applies a whitelisted-free JSON patch to a model row (admin only).
+func (s *Server) patchModel(w http.ResponseWriter, r *http.Request, dest interface{}, id string) {
+	if !s.requireAdmin(w, r) {
+		return
+	}
+	if err := s.db.First(dest, "id = ?", id).Error; err != nil {
+		writeError(w, http.StatusNotFound, "찾을 수 없습니다")
+		return
+	}
+	var patch map[string]interface{}
+	if err := decodeJSON(r, &patch); err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	delete(patch, "id")
+	if err := s.db.Model(dest).Updates(patch).Error; err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	s.db.First(dest, "id = ?", id)
+	writeJSON(w, http.StatusOK, dest)
+}
+
+func (s *Server) handlePatchCompany(w http.ResponseWriter, r *http.Request) {
+	s.patchModel(w, r, &models.Company{}, chi.URLParam(r, "id"))
+}
+func (s *Server) handleDeleteCompany(w http.ResponseWriter, r *http.Request) {
+	if !s.requireAdmin(w, r) {
+		return
+	}
+	s.db.Delete(&models.Company{}, "id = ?", chi.URLParam(r, "id"))
+	writeJSON(w, http.StatusOK, map[string]bool{"ok": true})
+}
+func (s *Server) handlePatchProduct(w http.ResponseWriter, r *http.Request) {
+	s.patchModel(w, r, &models.Product{}, chi.URLParam(r, "id"))
+}
+func (s *Server) handleDeleteProduct(w http.ResponseWriter, r *http.Request) {
+	if !s.requireAdmin(w, r) {
+		return
+	}
+	s.db.Delete(&models.Product{}, "id = ?", chi.URLParam(r, "id"))
+	writeJSON(w, http.StatusOK, map[string]bool{"ok": true})
+}
+func (s *Server) handlePatchVersion(w http.ResponseWriter, r *http.Request) {
+	s.patchModel(w, r, &models.Version{}, chi.URLParam(r, "id"))
+}
+func (s *Server) handleDeleteVersion(w http.ResponseWriter, r *http.Request) {
+	if !s.requireAdmin(w, r) {
+		return
+	}
+	s.db.Delete(&models.Version{}, "id = ?", chi.URLParam(r, "id"))
+	writeJSON(w, http.StatusOK, map[string]bool{"ok": true})
+}
+
 // ---- projects -------------------------------------------------------------
 
 // myProjectIDs returns the project IDs the caller is a member of (or PM of).
diff --git a/internal/httpapi/router.go b/internal/httpapi/router.go
index 00a86ef..143750d 100644
--- a/internal/httpapi/router.go
+++ b/internal/httpapi/router.go
@@ -98,10 +98,16 @@ func NewRouter(db *gorm.DB, store *storage.Storage, cfg config.Config, pusher *p
 			// ---- slice 3: projects ----
 			r.Get("/companies", s.handleListCompanies)
 			r.Post("/companies", s.handleCreateCompany)
+			r.Patch("/companies/{id}", s.handlePatchCompany)
+			r.Delete("/companies/{id}", s.handleDeleteCompany)
 			r.Get("/products", s.handleListProducts)
 			r.Post("/products", s.handleCreateProduct)
+			r.Patch("/products/{id}", s.handlePatchProduct)
+			r.Delete("/products/{id}", s.handleDeleteProduct)
 			r.Get("/versions", s.handleListVersions)
 			r.Post("/versions", s.handleCreateVersion)
+			r.Patch("/versions/{id}", s.handlePatchVersion)
+			r.Delete("/versions/{id}", s.handleDeleteVersion)
 			r.Get("/projects", s.handleListProjects)
 			r.Post("/projects", s.handleCreateProject)
 			r.Get("/projects/{id}", s.handleGetProject)
@@ -153,6 +159,7 @@ func NewRouter(db *gorm.DB, store *storage.Storage, cfg config.Config, pusher *p
 			r.Get("/taxes", s.handleListTaxes)
 			r.Post("/taxes", s.handleCreateTax)
 			r.Patch("/taxes/{taxId}", s.handlePatchTax)
+			r.Delete("/taxes/{taxId}", s.handleDeleteTax)
 			r.Get("/accounting/summary", s.handleAccountingSummary)   // cashflow vs incentive gap
 
 			// ---- slice 6: dashboard ----