diff --git a/backend/db/crud_question.py b/backend/db/crud_question.py
index 0c6f1066..660edd3b 100644
--- a/backend/db/crud_question.py
+++ b/backend/db/crud_question.py
@@ -29,7 +29,9 @@ def get_question_by_commodity(
     res = []
     for param in params:
         commodity = (
-            session.query(Commodity).filter(Commodity.id == param["commodity"]).first()
+            session.query(Commodity)
+            .filter(Commodity.id == param["commodity"])
+            .first()
         )
         commodity = commodity.to_question_list
         commodity_category_id = commodity["commodity_category_id"]
@@ -37,7 +39,8 @@ def get_question_by_commodity(
             session.query(Question)
             .join(CommodityCategoryQuestion)
             .filter(
-                CommodityCategoryQuestion.commodity_category == commodity_category_id,
+                CommodityCategoryQuestion.commodity_category
+                == commodity_category_id,
             )
             .all()
         )
@@ -45,7 +48,8 @@ def get_question_by_commodity(
         if not param["breakdown"]:
             questions = list(
                 filter(
-                    lambda question: question["id"] == 1 or question["parent"] == 1,
+                    lambda question: question["id"] == 1
+                    or question["parent"] == 1,
                     questions,
                 )
             )
@@ -54,9 +58,13 @@ def get_question_by_commodity(
     return res
 
 
-def get_question_by_case(session: Session, case_id: int) -> List[QuestionGroupListDict]:
+def get_question_by_case(
+    session: Session, case_id: int
+) -> List[QuestionGroupListDict]:
     case_commodity = (
-        session.query(CaseCommodity).filter(CaseCommodity.case == case_id).all()
+        session.query(CaseCommodity)
+        .filter(CaseCommodity.case == case_id)
+        .all()
     )
     commodities = (
         session.query(Commodity)
@@ -71,7 +79,8 @@ def get_question_by_case(session: Session, case_id: int) -> List[QuestionGroupLi
             session.query(Question)
             .join(CommodityCategoryQuestion)
             .filter(
-                CommodityCategoryQuestion.commodity_category == commodity_category_id,
+                CommodityCategoryQuestion.commodity_category
+                == commodity_category_id,
             )
             .all()
         )
@@ -93,3 +102,9 @@ def get_question_by_case(session: Session, case_id: int) -> List[QuestionGroupLi
         }
     )
     return res
+
+
+def get_question_by_created_by(session: Session, created_by=int):
+    return (
+        session.query(Question).filter(Question.created_by == created_by).all()
+    )
diff --git a/backend/db/crud_reference_data.py b/backend/db/crud_reference_data.py
index 9ae91181..af3e1811 100644
--- a/backend/db/crud_reference_data.py
+++ b/backend/db/crud_reference_data.py
@@ -171,3 +171,11 @@ def delete_reference(session: Session, id: int):
     session.delete(data)
     session.commit()
     session.flush()
+
+
+def get_reference_by_created_by(session: Session, created_by: int):
+    return (
+        session.query(ReferenceData)
+        .filter(ReferenceData.created_by == created_by)
+        .all()
+    )
diff --git a/backend/models/question.py b/backend/models/question.py
index a5593aa3..cd7bf466 100644
--- a/backend/models/question.py
+++ b/backend/models/question.py
@@ -53,10 +53,14 @@ class Question(Base):
     text = Column(String, nullable=False)
     description = Column(String, nullable=True)
     default_value = Column(String, nullable=True)
-    created_by = Column(Integer, ForeignKey("user.id"), nullable=True, default=None)
+    created_by = Column(
+        Integer, ForeignKey("user.id"), nullable=True, default=None
+    )
 
     children = relationship("Question")
-    parent_detail = relationship("Question", remote_side=[id], overlaps="children")
+    parent_detail = relationship(
+        "Question", remote_side=[id], overlaps="children"
+    )
     created_by_user = relationship(
         User, cascade="all, delete", passive_deletes=True, backref="questions"
     )
diff --git a/backend/models/reference_data.py b/backend/models/reference_data.py
index 6d9afb21..dc601863 100644
--- a/backend/models/reference_data.py
+++ b/backend/models/reference_data.py
@@ -137,25 +137,25 @@ def __init__(
         year: str,
         source: str,
         link: str,
-        notes: Optional[str],
-        confidence_level: Optional[str],
-        range: Optional[str],
-        area: Optional[str],
-        volume: Optional[str],
-        price: Optional[str],
-        cost_of_production: Optional[str],
-        diversified_income: Optional[str],
-        area_size_unit: Optional[str],
-        volume_measurement_unit: Optional[str],
-        cost_of_production_unit: Optional[str],
-        diversified_income_unit: Optional[str],
-        price_unit: Optional[str],
-        type_area: Optional[str],
-        type_volume: Optional[str],
-        type_price: Optional[str],
-        type_cost_of_production: Optional[str],
-        type_diversified_income: Optional[str],
-        created_by: Optional[str],
+        notes: Optional[str] = None,
+        confidence_level: Optional[str] = None,
+        range: Optional[str] = None,
+        area: Optional[str] = None,
+        volume: Optional[str] = None,
+        price: Optional[str] = None,
+        cost_of_production: Optional[str] = None,
+        diversified_income: Optional[str] = None,
+        area_size_unit: Optional[str] = None,
+        volume_measurement_unit: Optional[str] = None,
+        cost_of_production_unit: Optional[str] = None,
+        diversified_income_unit: Optional[str] = None,
+        price_unit: Optional[str] = None,
+        type_area: Optional[str] = None,
+        type_volume: Optional[str] = None,
+        type_price: Optional[str] = None,
+        type_cost_of_production: Optional[str] = None,
+        type_diversified_income: Optional[str] = None,
+        created_by: Optional[int] = None,
         id: Optional[int] = None,
     ):
         self.id = id
diff --git a/backend/routes/user.py b/backend/routes/user.py
index c9807a2c..0610946a 100644
--- a/backend/routes/user.py
+++ b/backend/routes/user.py
@@ -5,6 +5,8 @@
 import db.crud_case as crud_case
 import db.crud_user_case_access as crud_uca
 import db.crud_tag as crud_tag
+import db.crud_question as crud_question
+import db.crud_reference_data as crud_ref_data
 
 from math import ceil
 from middleware import (
@@ -444,19 +446,22 @@ def delete(
     if cases_owned_by_user:
         raise HTTPException(
             status_code=status.HTTP_409_CONFLICT,
-            detail=f"user {id} owned a case",
+            detail={
+                "id": user.id,
+                "email": user.email,
+                "cases": [case.to_dropdown for case in cases_owned_by_user],
+            },
         )
 
-    # Ensure that the 'case updated_by' field is moved into the case owner.
+    # Ensure that the case updated by deleted user also clean
+    # by move created_by value into updated_by column
     cases_updated_by_user = crud_case.get_case_by_updated_by(
         session=session, updated_by=user.id
     )
     if cases_updated_by_user:
         for case in cases_updated_by_user:
             case.updated_by = case.created_by
-            session.commit()
-            session.flush()
-            session.refresh(case)
+        session.commit()
 
     # Confirm that the user's case access is removed.
     crud_uca.delete_case_access_by_user_id(session=session, user_id=user.id)
@@ -471,14 +476,29 @@ def delete(
     if tags:
         for tag in tags:
             tag.created_by = None
-            session.commit()
-            session.flush()
-            session.refresh(tag)
+        session.commit()
 
-    # question created by user?
-    # reference data created by user?
+    # Verify user's ID removed from questions created_by the user
+    questions = crud_question.get_question_by_created_by(
+        session=session, created_by=user.id
+    )
+    if questions:
+        for question in questions:
+            question.created_by = None
+        session.commit()
+
+    # Verify user's ID removed from reference created_by the user
+    references = crud_ref_data.get_reference_by_created_by(
+        session=session, created_by=user.id
+    )
+    if references:
+        for reference in references:
+            reference.created_by = None
+            session.flush()
+            session.commit()
+            session.refresh(reference)
 
-    # delete user
+    # finally delete user
     crud_user.delete_user(session=session, id=user.id)
     return Response(status_code=HTTPStatus.NO_CONTENT.value)
 
diff --git a/backend/tests/test_1010_user_deletion.py b/backend/tests/test_1010_user_deletion.py
index b10731ad..7781cbe2 100644
--- a/backend/tests/test_1010_user_deletion.py
+++ b/backend/tests/test_1010_user_deletion.py
@@ -10,6 +10,9 @@
 from models.user_case_access import UserCaseAccess
 from models.user_business_unit import UserBusinessUnit
 from models.tag import Tag
+from models.question import Question
+from models.reference_data import ReferenceData
+from models.user import User
 
 
 pytestmark = pytest.mark.asyncio
@@ -41,6 +44,16 @@ async def test_deleting_a_user_who_has_cases(
             headers={"Authorization": f"Bearer {account.token}"},
         )
         assert res.status_code == 409
+        res = res.json()
+        assert res == {
+            "detail": {
+                "id": 1,
+                "email": "super_admin@akvo.org",
+                "cases": [
+                    {"label": "Bali Coffee Production (Private)", "value": 2}
+                ],
+            }
+        }
 
     @pytest.mark.asyncio
     async def test_deleting_a_user_who_doesnt_have_cases(
@@ -100,6 +113,38 @@ async def test_deleting_a_user_who_doesnt_have_cases(
         assert tag is not None
         assert tag.created_by == deleted_user
 
+        # add question
+        question_id = 1000
+        question = Question(
+            id=question_id, text="Test Question 1000", created_by=deleted_user
+        )
+        session.add(question)
+        session.commit()
+        session.flush()
+        session.refresh(question)
+        assert question is not None
+        assert question.created_by == deleted_user
+
+        # add reference_data
+        reference_id = 10000
+        reference = ReferenceData(
+            id=reference_id,
+            country=1,
+            commodity=1,
+            region="asia",
+            currency="usd",
+            year="2020",
+            source="source",
+            link="link",
+            created_by=deleted_user,
+        )
+        session.add(reference)
+        session.commit()
+        session.flush()
+        session.refresh(reference)
+        assert reference is not None
+        assert reference.created_by == deleted_user
+
         # delete user
         res = await client.delete(
             app.url_path_for("user:delete", user_id=deleted_user),
@@ -132,3 +177,22 @@ async def test_deleting_a_user_who_doesnt_have_cases(
         # make sure tag created_by removed
         tag = session.query(Tag).filter(Tag.created_by == deleted_user).first()
         assert tag is None
+
+        # make sure question created_by is None
+        question = (
+            session.query(Question).filter(Question.id == question_id).first()
+        )
+        assert question is not None
+        assert question.id == question_id
+        assert question.created_by is None
+
+        # make sure reference data created by is None
+        reference_data = (
+            session.query(ReferenceData)
+            .filter(ReferenceData.created_by == deleted_user)
+            .all()
+        )
+        assert reference_data == []
+
+        user = session.query(User).filter(User.id == deleted_user).first()
+        assert user is None
diff --git a/frontend/src/pages/admin/users/Users.js b/frontend/src/pages/admin/users/Users.js
index e61c2237..7d802626 100644
--- a/frontend/src/pages/admin/users/Users.js
+++ b/frontend/src/pages/admin/users/Users.js
@@ -1,10 +1,10 @@
-import React, { useEffect, useState } from "react";
+import React, { useEffect, useState, useCallback } from "react";
 import { ContentLayout, TableContent } from "../../../components/layout";
 import { Link } from "react-router-dom";
-import { EditOutlined } from "@ant-design/icons";
+import { EditOutlined, DeleteTwoTone } from "@ant-design/icons";
 import upperFirst from "lodash/upperFirst";
 import { api } from "../../../lib";
-import { Checkbox, Select } from "antd";
+import { Button, Checkbox, Select, Space, Popconfirm, Modal, List } from "antd";
 import { selectProps } from "../../cases/components";
 import "./user.scss";
 
@@ -18,7 +18,7 @@ const defData = {
 
 const filterProps = {
   ...selectProps,
-  style: { width: window.innerHeight * 0.225 },
+  style: { width: window.innerHeight * 0.175 },
 };
 
 const userRoleOptions = [
@@ -47,32 +47,87 @@ const Users = () => {
   const [data, setData] = useState(defData);
   const [showApprovedUser, setShowApprovedUser] = useState(true);
   const [role, setRole] = useState(null);
+  const [deleting, setDeleting] = useState([]);
+  const [modal, contextHolder] = Modal.useModal();
+
+  const fetchUser = useCallback(
+    ({ currentPage, search, showApprovedUser, role }) => {
+      setLoading(true);
+      let url = `user?page=${currentPage}&limit=${perPage}&approved=${showApprovedUser}`;
+      if (search) {
+        url = `${url}&search=${search}`;
+      }
+      if (role) {
+        url = `${url}&role=${role}`;
+      }
+      api
+        .get(url)
+        .then((res) => {
+          setData(res.data);
+        })
+        .catch((e) => {
+          console.error(e.response);
+          const { status } = e.response;
+          if (status === 404) {
+            setData(defData);
+          }
+        })
+        .finally(() => {
+          setLoading(false);
+        });
+    },
+    []
+  );
 
   useEffect(() => {
-    setLoading(true);
-    let url = `user?page=${currentPage}&limit=${perPage}&approved=${showApprovedUser}`;
-    if (search) {
-      url = `${url}&search=${search}`;
-    }
-    if (role) {
-      url = `${url}&role=${role}`;
-    }
+    fetchUser({ currentPage, search, showApprovedUser, role });
+  }, [currentPage, search, showApprovedUser, role, fetchUser]);
+
+  const handleDeleteUser = (user) => {
+    setDeleting((prev) => [...prev, user.id]);
     api
-      .get(url)
-      .then((res) => {
-        setData(res.data);
+      .delete(`user/${user.id}`)
+      .then(() => {
+        fetchUser({ currentPage, search, showApprovedUser, role });
       })
       .catch((e) => {
-        console.error(e.response);
-        const { status } = e.response;
-        if (status === 404) {
-          setData(defData);
+        const { status, data } = e.response;
+        if (status === 409) {
+          const { cases } = data.detail;
+          // show the case names and add a button "Go to cases"
+          modal.confirm({
+            title: `Unable to delete user ${user.email}`,
+            content: (
+              <div style={{ marginLeft: "-26px" }}>
+                <h4>The following cases are still owned by this user:</h4>
+                <List
+                  header={null}
+                  footer={null}
+                  size="small"
+                  bordered
+                  style={{ maxHeight: "200px", overflow: "auto" }}
+                  dataSource={cases}
+                  renderItem={(item) => <List.Item>{item.label}</List.Item>}
+                />
+                <p>
+                  Please assign new owners for these cases before deleting this
+                  user.
+                </p>
+              </div>
+            ),
+            okText: "Go to cases",
+            onOk: () => {
+              const URL = `/cases?owner=${user.email}`;
+              window.open(URL, "_blank");
+            },
+            cancelText: "Cancel",
+          });
         }
       })
       .finally(() => {
-        setLoading(false);
+        setDeleting((prev) => prev.filter((id) => id !== user.id));
       });
-  }, [currentPage, search, showApprovedUser, role]);
+  };
 
   const columns = [
     {
@@ -114,9 +169,27 @@ const Users = () => {
       width: "5%",
       align: "center",
       render: (text, record) => (
-        <Link to={`/admin/user/${record.id}`}>
-          <EditOutlined />
-        </Link>
+        <Space align="center">
+          <Link to={`/admin/user/${record.id}`}>
+            <EditOutlined style={{ marginTop: "5px" }} />
+          </Link>
+          <Popconfirm
+            title="Delete User"
+            description={`Are you sure to delete user ${record.email}?`}
+            onConfirm={() => handleDeleteUser(record)}
+            okText="Yes"
+            cancelText="No"
+            placement="leftBottom"
+          >
+            <Button
+              size="small"
+              type="text"
+              icon={<DeleteTwoTone twoToneColor="#eb2f96" />}
+              loading={deleting.find((id) => id === record.id) ? true : false}
+              disabled={deleting.length ? true : false}
+            />
+          </Popconfirm>
+        </Space>
       ),
     },
   ];
@@ -173,6 +246,8 @@ const Users = () => {
           />
         }
       />
+      {/* modal context holder */}
+      {contextHolder}
     </ContentLayout>
   );
 };
diff --git a/frontend/src/pages/cases/Cases.js b/frontend/src/pages/cases/Cases.js
index 2b153c28..5e3c2f79 100644
--- a/frontend/src/pages/cases/Cases.js
+++ b/frontend/src/pages/cases/Cases.js
@@ -1,6 +1,6 @@
 import React, { useEffect, useState, useMemo } from "react";
 import { ContentLayout, TableContent } from "../../components/layout";
-import { Link } from "react-router-dom";
+import { Link, useSearchParams } from "react-router-dom";
 import {
   EditOutlined,
   UserSwitchOutlined,
@@ -39,6 +39,9 @@ const filterProps = {
 };
 
 const Cases = () => {
+  const [searchParams] = useSearchParams();
+  const caseOwner = searchParams.get("owner");
+
   const [loading, setLoading] = useState(false);
   const [currentPage, setCurrentPage] = useState(1);
   const [search, setSearch] = useState(null);
@@ -46,7 +49,7 @@ const Cases = () => {
   const [country, setCountry] = useState(null);
   const [commodity, setCommodity] = useState(null);
   const [tags, setTags] = useState([]);
-  const [email, setEmail] = useState(null);
+  const [email, setEmail] = useState(caseOwner || null);
   const [year, setYear] = useState(null);
 
   const tagOptions = UIState.useState((s) => s.tagOptions);
@@ -178,6 +181,19 @@ const Cases = () => {
       defaultSortOrder: "descend",
       sorter: (a, b) => a.name.localeCompare(b.name),
     },
+    {
+      title: "Primary Commodity",
+      key: "primary_commodity",
+      render: (record) => {
+        const findPrimaryCommodity = commodityOptios.find(
+          (co) => co.value === record.focus_commodity
+        );
+        if (!findPrimaryCommodity?.label) {
+          return "-";
+        }
+        return findPrimaryCommodity.label;
+      },
+    },
     {
       title: "Tags",
       key: "tags",
@@ -212,7 +228,7 @@ const Cases = () => {
         }
         if (row.id === showChangeOwnerForm) {
           return (
-            <Row align="center" gutter={[8, 8]}>
+            <Row align="center" gutter={[6, 6]}>
               <Col span={20}>
                 <DebounceSelect
                   placeholder="Search for a user"
@@ -350,12 +366,14 @@ const Cases = () => {
         key="4"
         placeholder="Case owner email"
         onChange={(e) => setEmail(e.target.value)}
+        value={email}
       />
       <InputNumber
         key="5"
         placeholder="Year"
         controls={false}
         onChange={setYear}
+        value={year}
       />
     </Space>
   );