diff --git a/src/app/(main)/projects/create/sub/page.tsx b/src/app/(main)/projects/create/sub/page.tsx
index bd5837e..1a8fab7 100644
--- a/src/app/(main)/projects/create/sub/page.tsx
+++ b/src/app/(main)/projects/create/sub/page.tsx
@@ -1,6 +1,7 @@
 import { fetchAllCustomers, fetchAllSubsidiaries } from "@/app/api/customer";
 import { fetchGrades } from "@/app/api/grades";
 import {
+    fetchMainProjects,
     fetchProjectBuildingTypes,
     fetchProjectCategories,
     fetchProjectContractTypes,
@@ -12,10 +13,12 @@ import {
 } from "@/app/api/projects";
 import { preloadStaff, preloadTeamLeads } from "@/app/api/staff";
 import { fetchAllTasks, fetchTaskTemplates } from "@/app/api/tasks";
+import { ServerFetchError } from "@/app/utils/fetchUtil";
 import CreateProject from "@/components/CreateProject";
 import { I18nProvider, getServerI18n } from "@/i18n";
 import Typography from "@mui/material/Typography";
 import { Metadata } from "next";
+import { notFound } from "next/navigation";
 
 export const metadata: Metadata = {
     title: "Create Project",
@@ -39,12 +42,21 @@ const Projects: React.FC = async () => {
     fetchGrades();
     preloadTeamLeads();
     preloadStaff();
+    try {
+        const data = await fetchMainProjects();
+
+        if (!Boolean(data) || data.length === 0) {
+            notFound();
+        }
+    } catch (e) {
+        notFound();
+    }
 
     return (
         <>
             <Typography variant="h4">{t("Create Sub Project")}</Typography>
             <I18nProvider namespaces={["projects"]}>
-                <CreateProject isEditMode={false}/>
+                <CreateProject isEditMode={false} isSubProject={true} />
             </I18nProvider>
         </>
     );
diff --git a/src/app/api/projects/actions.ts b/src/app/api/projects/actions.ts
index c1be476..97cb34e 100644
--- a/src/app/api/projects/actions.ts
+++ b/src/app/api/projects/actions.ts
@@ -22,6 +22,7 @@ export interface CreateProjectInputs {
   projectActualEnd: string;
   projectStatus: string;
   isClpProject: boolean;
+  mainProjectId?: number | null;
 
   // Project info
   serviceTypeId: number;
diff --git a/src/app/api/projects/index.ts b/src/app/api/projects/index.ts
index 7a64ea1..d25ba16 100644
--- a/src/app/api/projects/index.ts
+++ b/src/app/api/projects/index.ts
@@ -15,6 +15,27 @@ export interface ProjectResult {
   status: string;
 }
 
+export interface MainProject {
+  projectId: number;
+  projectCode: string;
+  projectName: string;
+  projectCategoryId: number;
+  projectDescription: string;
+  projectLeadId: number;
+  projectStatus: string;
+  isClpProject: boolean;
+  serviceTypeId: number;
+  fundingTypeId: number;
+  contractTypeId: number;
+  locationId: number;
+  buildingTypeIds: number[];
+  workNatureIds: number[];
+  clientId: number;
+  clientContactId: number;
+  clientSubsidiaryId: number;
+  expectedProjectFee: number;
+}
+
 export interface ProjectCategory {
   id: number;
   name: string;
@@ -82,7 +103,7 @@ export const fetchProjects = cache(async () => {
 });
 
 export const fetchMainProjects = cache(async () => {
-  return serverFetchJson<ProjectResult[]>(`${BASE_API_URL}/projects/main`, {
+  return serverFetchJson<MainProject[]>(`${BASE_API_URL}/projects/main`, {
     next: { tags: ["projects"] },
   });
 });
diff --git a/src/components/Breadcrumb/Breadcrumb.tsx b/src/components/Breadcrumb/Breadcrumb.tsx
index 516aca2..8c1b9b0 100644
--- a/src/components/Breadcrumb/Breadcrumb.tsx
+++ b/src/components/Breadcrumb/Breadcrumb.tsx
@@ -15,7 +15,9 @@ const pathToLabelMap: { [path: string]: string } = {
   "/home": "User Workspace",
   "/projects": "Projects",
   "/projects/create": "Create Project",
+  "/projects/create/sub": "Sub Project",
   "/projects/edit": "Edit Project",
+  "/projects/edit/sub": "Sub Project",
   "/tasks": "Task Template",
   "/tasks/create": "Create Task Template",
   "/staffReimbursement": "Staff Reimbursement",
diff --git a/src/components/ControlledAutoComplete/ControlledAutoComplete.tsx b/src/components/ControlledAutoComplete/ControlledAutoComplete.tsx
index d8a2962..e37f348 100644
--- a/src/components/ControlledAutoComplete/ControlledAutoComplete.tsx
+++ b/src/components/ControlledAutoComplete/ControlledAutoComplete.tsx
@@ -10,7 +10,7 @@ const icon = <CheckBoxOutlineBlankIcon fontSize="medium" />;
 const checkedIcon = <CheckBoxIcon fontSize="medium" />;
 // label -> e.g. code - name -> 001 - WL
 // name -> WL
-interface Props<T extends { id?: number | string; label?: string; name?: string }, TField extends FieldValues> {
+interface Props<T extends { id?: number | string | null; label?: string; name?: string }, TField extends FieldValues> {
     control: Control<TField>,
     options: T[],
     name: Path<TField>, // register name
@@ -18,7 +18,6 @@ interface Props<T extends { id?: number | string; label?: string; name?: string
     noOptionsText?: string,
     isMultiple?: boolean,
     rules?: RegisterOptions<FieldValues>
-    error?: boolean,
 }
 
 function ControlledAutoComplete<
@@ -28,68 +27,78 @@ function ControlledAutoComplete<
     props: Props<T, TField>
 ) {
     const { t } = useTranslation()
-    const { control, options, name, label, noOptionsText, isMultiple, rules, error } = props;
+    const { control, options, name, label, noOptionsText, isMultiple, rules } = props;
+
+    // set default value if value is null
+    if (!Boolean(isMultiple) && !Boolean(control._formValues[name])) {
+        console.log(name, control._formValues[name])
+        control._formValues[name] = options[0]?.id ?? undefined
+    } else if (Boolean(isMultiple) && !Boolean(control._formValues[name])) {
+        control._formValues[name] = []
+    }
 
     return (
         <Controller
             name={name}
             control={control}
             rules={rules}
-            render={({ field }) => (
-                isMultiple ?
-                    <Autocomplete
-                        multiple
-                        disableClearable
-                        disableCloseOnSelect
-                        disablePortal
-                        noOptionsText={noOptionsText ?? t("No Options")}
-                        value={options.filter(option => {
-                            // console.log(field.value)
-                            return field.value?.includes(option.id)
-                        })}
-                        options={options}
-                        getOptionLabel={(option) => option.label ?? option.name!!}
-                        isOptionEqualToValue={(option, value) => option.id === value.id}
-                        renderOption={(params, option, { selected }) => {
-                            return (
-                                <li {...params}>
-                                    <Checkbox
-                                        icon={icon}
-                                        checkedIcon={checkedIcon}
-                                        checked={selected}
-                                        style={{ marginRight: 8 }}
-                                    />
-                                    {option.label ?? option.name}
-                                </li>
-                            );
-                        }}
-                        onChange={(event, value) => {
-                            field.onChange(value?.map(v => v.id))
-                        }}
-                        renderInput={(params) => <TextField {...params} error={error} variant="outlined" label={label} />}
-                    />
-                    :
-                    <Autocomplete
-                        disableClearable
-                        disablePortal
-                        noOptionsText={noOptionsText ?? t("No Options")}
-                        value={options.find(option => option.id === field.value) ?? options[0]}
-                        options={options}
-                        getOptionLabel={(option) => option.label ?? option.name!!}
-                        isOptionEqualToValue={(option, value) => option.id === value.id}
-                        renderOption={(params, option) => {
-                            return (
-                                <MenuItem {...params} key={option.id} value={option.id}>
-                                    {option.label ?? option.name}
-                                </MenuItem>
-                            );
-                        }}
-                        onChange={(event, value) => {
-                            field.onChange(value?.id)
-                        }}
-                        renderInput={(params) => <TextField {...params} error={error} variant="outlined" label={label} />}
-                    />
-            )}
+
+            render={({ field, fieldState, formState }) => {
+
+                return (
+                    isMultiple ?
+                        <Autocomplete
+                            multiple
+                            disableClearable
+                            disableCloseOnSelect
+                            disablePortal
+                            noOptionsText={noOptionsText ?? t("No Options")}
+                            value={options.filter(option => {
+                                return field.value?.includes(option.id)
+                            })}
+                            options={options}
+                            getOptionLabel={(option) => option.label ?? option.name!!}
+                            isOptionEqualToValue={(option, value) => option.id === value.id}
+                            renderOption={(params, option, { selected }) => {
+                                return (
+                                    <li {...params} key={option.id}>
+                                        <Checkbox
+                                            icon={icon}
+                                            checkedIcon={checkedIcon}
+                                            checked={selected}
+                                            style={{ marginRight: 8 }}
+                                        />
+                                        {option.label ?? option.name}
+                                    </li>
+                                );
+                            }}
+                            onChange={(event, value) => {
+                                field.onChange(value?.map(v => v.id))
+                            }}
+                            renderInput={(params) => <TextField {...params} error={Boolean(formState.errors[name])} variant="outlined" label={label} />}
+                        />
+                        :
+                        <Autocomplete
+                            disableClearable
+                            disablePortal
+                            noOptionsText={noOptionsText ?? t("No Options")}
+                            value={options.find(option => option.id === field.value) ?? options[0]}
+                            options={options}
+                            getOptionLabel={(option) => option.label ?? option.name!!}
+                            isOptionEqualToValue={(option, value) => option?.id === value?.id}
+                            renderOption={(params, option) => {
+                                return (
+                                    <MenuItem {...params} key={option.id} value={option.id}>
+                                        {option.label ?? option.name}
+                                    </MenuItem>
+                                );
+                            }}
+                            onChange={(event, value) => {
+                                field.onChange(value?.id)
+                            }}
+                            renderInput={(params) => <TextField {...params} error={Boolean(formState.errors[name])} variant="outlined" label={label} />}
+                        />)
+            }}
         />
     )
 }
diff --git a/src/components/CreateProject/CreateProject.tsx b/src/components/CreateProject/CreateProject.tsx
index 937bac5..5f35919 100644
--- a/src/components/CreateProject/CreateProject.tsx
+++ b/src/components/CreateProject/CreateProject.tsx
@@ -33,6 +33,7 @@ import {
   ContractType,
   FundingType,
   LocationType,
+  MainProject,
   ProjectCategory,
   ServiceType,
   WorkNature,
@@ -52,6 +53,8 @@ import dayjs from "dayjs";
 
 export interface Props {
   isEditMode: boolean;
+  isSubProject: boolean;
+  mainProjects?: MainProject[];
   defaultInputs?: CreateProjectInputs;
   allTasks: Task[];
   projectCategories: ProjectCategory[];
@@ -93,6 +96,8 @@ const hasErrorsInTab = (
 
 const CreateProject: React.FC<Props> = ({
   isEditMode,
+  isSubProject,
+  mainProjects,
   defaultInputs,
   allTasks,
   projectCategories,
@@ -269,14 +274,9 @@ const CreateProject: React.FC<Props> = ({
       milestones: {},
       totalManhour: 0,
       taskTemplateId: "All",
-      projectCategoryId: projectCategories.length > 0 ? projectCategories[0].id : undefined,
-      projectLeadId: teamLeads.length > 0 ? teamLeads[0].id : undefined,
-      serviceTypeId: serviceTypes.length > 0 ? serviceTypes[0].id : undefined,
-      fundingTypeId: fundingTypes.length > 0 ? fundingTypes[0].id : undefined,
-      contractTypeId: contractTypes.length > 0 ? contractTypes[0].id : undefined,
-      locationId: locationTypes.length > 0 ? locationTypes[0].id : undefined,
-      clientSubsidiaryId: undefined,
-      clientId: allCustomers.length > 0 ? allCustomers[0].id : undefined,
+      projectName: mainProjects !== undefined ? mainProjects[0].projectName : undefined,
+      projectDescription: mainProjects !== undefined ? mainProjects[0].projectDescription : undefined,
+      expectedProjectFee: mainProjects !== undefined ? mainProjects[0].expectedProjectFee : undefined,
       ...defaultInputs,
 
       // manhourPercentageByGrade should have a sensible default
@@ -380,6 +380,8 @@ const CreateProject: React.FC<Props> = ({
           </Tabs>
           {
             <ProjectClientDetails
+              isSubProject={isSubProject}
+              mainProjects={mainProjects}
               buildingTypes={buildingTypes}
               workNatures={workNatures}
               contractTypes={contractTypes}
diff --git a/src/components/CreateProject/CreateProjectWrapper.tsx b/src/components/CreateProject/CreateProjectWrapper.tsx
index 6ce6242..3d70225 100644
--- a/src/components/CreateProject/CreateProjectWrapper.tsx
+++ b/src/components/CreateProject/CreateProjectWrapper.tsx
@@ -1,6 +1,7 @@
 import { fetchAllTasks, fetchTaskTemplates } from "@/app/api/tasks";
 import CreateProject from "./CreateProject";
 import {
+  fetchMainProjects,
   fetchProjectBuildingTypes,
   fetchProjectCategories,
   fetchProjectContractTypes,
@@ -14,10 +15,14 @@ import { fetchStaff, fetchTeamLeads } from "@/app/api/staff";
 import { fetchAllCustomers, fetchAllSubsidiaries } from "@/app/api/customer";
 import { fetchGrades } from "@/app/api/grades";
 
-type CreateProjectProps = { isEditMode: false };
+type CreateProjectProps = {
+  isEditMode: false;
+  isSubProject?: boolean;
+};
 interface EditProjectProps {
   isEditMode: true;
   projectId?: string;
+  isSubProject?: boolean;
 }
 
 type Props = CreateProjectProps | EditProjectProps;
@@ -59,9 +64,14 @@ const CreateProjectWrapper: React.FC<Props> = async (props) => {
     ? await fetchProjectDetails(props.projectId!)
     : undefined;
 
+  const mainProjects = Boolean(props.isSubProject)
+    ? await fetchMainProjects()
+    : undefined;
+
   return (
     <CreateProject
       isEditMode={props.isEditMode}
+      isSubProject={Boolean(props.isSubProject)}
       defaultInputs={projectInfo}
       allTasks={tasks}
       projectCategories={projectCategories}
@@ -77,6 +87,7 @@ const CreateProjectWrapper: React.FC<Props> = async (props) => {
       workNatures={workNatures}
       allStaffs={allStaffs}
       grades={grades}
+      mainProjects={mainProjects}
     />
   );
 };
diff --git a/src/components/CreateProject/ProjectClientDetails.tsx b/src/components/CreateProject/ProjectClientDetails.tsx
index d77defe..8fb7fab 100644
--- a/src/components/CreateProject/ProjectClientDetails.tsx
+++ b/src/components/CreateProject/ProjectClientDetails.tsx
@@ -22,6 +22,7 @@ import {
   ContractType,
   FundingType,
   LocationType,
+  MainProject,
   ProjectCategory,
   ServiceType,
   WorkNature,
@@ -37,6 +38,8 @@ import ControlledAutoComplete from "../ControlledAutoComplete/ControlledAutoComp
 
 interface Props {
   isActive: boolean;
+  isSubProject: boolean;
+  mainProjects?: MainProject[];
   projectCategories: ProjectCategory[];
   teamLeads: StaffResult[];
   allCustomers: Customer[];
@@ -51,6 +54,8 @@ interface Props {
 
 const ProjectClientDetails: React.FC<Props> = ({
   isActive,
+  isSubProject,
+  mainProjects,
   projectCategories,
   teamLeads,
   allCustomers,
@@ -70,6 +75,8 @@ const ProjectClientDetails: React.FC<Props> = ({
     control,
     setValue,
     getValues,
+    reset,
+    resetField,
   } = useFormContext<CreateProjectInputs>();
 
   const subsidiaryMap = useMemo<{
@@ -136,7 +143,6 @@ const ProjectClientDetails: React.FC<Props> = ({
   // Automatically add the team lead to the allocated staff list
   const selectedTeamLeadId = watch("projectLeadId");
   useEffect(() => {
-    console.log(selectedTeamLeadId)
     if (selectedTeamLeadId !== undefined) {
       const currentStaffIds = getValues("allocatedStaffIds");
       const newList = uniq([...currentStaffIds, selectedTeamLeadId]);
@@ -144,6 +150,32 @@ const ProjectClientDetails: React.FC<Props> = ({
     }
   }, [getValues, selectedTeamLeadId, setValue]);
 
+  // Automatically update the project & client details whene select a main project
+  const mainProjectId = watch("mainProjectId")
+  useEffect(() => {
+    if (mainProjectId !== undefined && mainProjects !== undefined) {
+      const mainProject = mainProjects.find(project => project.projectId === mainProjectId);
+
+      if (mainProject !== undefined) {
+        setValue("projectName", mainProject.projectName)
+        setValue("projectCategoryId", mainProject.projectCategoryId)
+        setValue("projectLeadId", mainProject.projectLeadId)
+        setValue("serviceTypeId", mainProject.serviceTypeId)
+        setValue("fundingTypeId", mainProject.fundingTypeId)
+        setValue("contractTypeId", mainProject.contractTypeId)
+        setValue("locationId", mainProject.locationId)
+        setValue("buildingTypeIds", mainProject.buildingTypeIds)
+        setValue("workNatureIds", mainProject.workNatureIds)
+        setValue("projectDescription", mainProject.projectDescription)
+        setValue("expectedProjectFee", mainProject.expectedProjectFee)
+        setValue("isClpProject", mainProject.isClpProject)
+        setValue("clientId", mainProject.clientId)
+        setValue("clientSubsidiaryId", mainProject.clientSubsidiaryId)
+        setValue("clientContactId", mainProject.clientContactId)
+      }
+    }
+  }, [getValues, mainProjectId, setValue])
+
   // const buildingTypeIdNameMap = buildingTypes.reduce<{ [id: number]: string }>(
   //   (acc, building) => ({ ...acc, [building.id]: building.name }),
   //   {},
@@ -162,6 +194,18 @@ const ProjectClientDetails: React.FC<Props> = ({
             {t("Project Details")}
           </Typography>
           <Grid container spacing={2} columns={{ xs: 6, sm: 12 }}>
+            {
+              isSubProject && mainProjects !== undefined && <><Grid item xs={6}>
+                <ControlledAutoComplete
+                  control={control}
+                  options={[...mainProjects.map(mainProject => ({ id: mainProject.projectId, label: `${mainProject.projectCode} - ${mainProject.projectName}` }))]}
+                  name="mainProjectId"
+                  label={t("Main Project")}
+                  noOptionsText={t("No Main Project")}
+                />
+              </Grid>
+                <Grid item sx={{ display: { xs: "none", sm: "block" } }} /></>
+            }
             <Grid item xs={6}>
               <TextField
                 label={t("Project Code")}
@@ -283,7 +327,7 @@ const ProjectClientDetails: React.FC<Props> = ({
             <Grid item xs={6}>
               <Checkbox
                 {...register("isClpProject")}
-                defaultChecked={watch("isClpProject")}
+                checked={Boolean(watch("isClpProject"))}
               />
               <Typography variant="overline" display="inline">
                 {t("CLP Project")}
@@ -317,7 +361,6 @@ const ProjectClientDetails: React.FC<Props> = ({
                 rules={{
                   required: "Please select a client"
                 }}
-                error={Boolean(errors.clientId)}
               />
             </Grid>
             <Grid item sx={{ display: { xs: "none", sm: "block" } }} />
@@ -337,7 +380,7 @@ const ProjectClientDetails: React.FC<Props> = ({
                 <Grid item xs={6}>
                   <ControlledAutoComplete
                     control={control}
-                    options={[{ id: undefined, label: t("No Subsidiary") }, ...customerSubsidiaryIds
+                    options={[{ label: t("No Subsidiary") }, ...customerSubsidiaryIds
                       .filter((subId) => subsidiaryMap[subId])
                       .map((subsidiaryId, index) => {
                         const subsidiary = subsidiaryMap[subsidiaryId]
@@ -368,7 +411,6 @@ const ProjectClientDetails: React.FC<Props> = ({
                         } else return true;
                       },
                     }}
-                    error={Boolean(errors.clientContactId)}
                   />
                 </Grid>
                 <Grid container sx={{ display: { xs: "none", sm: "block" } }} />
diff --git a/src/components/CreateProject/StaffAllocation.tsx b/src/components/CreateProject/StaffAllocation.tsx
index bd699ec..81d3c97 100644
--- a/src/components/CreateProject/StaffAllocation.tsx
+++ b/src/components/CreateProject/StaffAllocation.tsx
@@ -25,6 +25,7 @@ import {
   Tab,
   Tabs,
   SelectChangeEvent,
+  Autocomplete,
 } from "@mui/material";
 import differenceWith from "lodash/differenceWith";
 import intersectionWith from "lodash/intersectionWith";
diff --git a/src/components/CreateProject/TaskSetup.tsx b/src/components/CreateProject/TaskSetup.tsx
index dac0698..fe02f37 100644
--- a/src/components/CreateProject/TaskSetup.tsx
+++ b/src/components/CreateProject/TaskSetup.tsx
@@ -7,7 +7,7 @@ import Typography from "@mui/material/Typography";
 import { useTranslation } from "react-i18next";
 import TransferList from "../TransferList";
 import Button from "@mui/material/Button";
-import React, { useCallback, useMemo, useState } from "react";
+import React, { SyntheticEvent, useCallback, useMemo, useState } from "react";
 import CardActions from "@mui/material/CardActions";
 import RestartAlt from "@mui/icons-material/RestartAlt";
 import FormControl from "@mui/material/FormControl";
@@ -20,6 +20,7 @@ import { CreateProjectInputs, ManhourAllocation } from "@/app/api/projects/actio
 import isNumber from "lodash/isNumber";
 import intersectionWith from "lodash/intersectionWith";
 import { difference } from "lodash";
+import { Autocomplete, TextField } from "@mui/material";
 
 interface Props {
   allTasks: Task[];
@@ -50,9 +51,9 @@ const TaskSetup: React.FC<Props> = ({
     "All" | number
   >(watch("taskTemplateId") ?? "All");
   const onSelectTaskTemplate = useCallback(
-    (e: SelectChangeEvent<number | "All">) => {
-      if (e.target.value === "All" || isNumber(e.target.value)) {
-        setSelectedTaskTemplateId(e.target.value);
+    (event: SyntheticEvent<Element, Event>, value: NonNullable<{id: number | string, name: string}>) => {
+      if (value.id === "All" || isNumber(value.id)) {
+        setSelectedTaskTemplateId(value.id);
         // onReset();
       }
     },
@@ -132,21 +133,24 @@ const TaskSetup: React.FC<Props> = ({
           marginBlockEnd={1}
         >
           <Grid item xs={6}>
-            <FormControl fullWidth>
-              <InputLabel>{t("Task List Source")}</InputLabel>
-              <Select<"All" | number>
-                label={t("Task List Source")}
-                value={selectedTaskTemplateId}
-                onChange={onSelectTaskTemplate}
-              >
-                <MenuItem value={"All"}>{t("All tasks")}</MenuItem>
-                {taskTemplates.map((template, index) => (
-                  <MenuItem key={`${template.id}-${index}`} value={template.id}>
-                    {template.name}
+            <Autocomplete
+              disableClearable
+              disablePortal
+              noOptionsText={t("No Task List Source")}
+              value={taskTemplates.find(taskTemplate => taskTemplate.id === selectedTaskTemplateId)}
+              options={[{id: "All", name: t("All tasks")}, ...taskTemplates.map(taskTemplate => ({id: taskTemplate.id, name: taskTemplate.name}))]}
+              getOptionLabel={(taskTemplate) => taskTemplate.name}
+              isOptionEqualToValue={(option, value) => option?.id === value?.id}
+              renderOption={(params, option) => {
+                return (
+                  <MenuItem {...params} key={option.id} value={option.id}>
+                    {option.name}
                   </MenuItem>
-                ))}
-              </Select>
-            </FormControl>
+                );
+              }}
+              onChange={onSelectTaskTemplate}
+              renderInput={(params) => <TextField {...params} variant="outlined" label={t("Task List Source")} />}
+            />
           </Grid>
         </Grid>
         <TransferList