diff --git a/pages/api/attendees/index.ts b/pages/api/attendees/index.ts
index 509907bb8d..59561c736e 100644
--- a/pages/api/attendees/index.ts
+++ b/pages/api/attendees/index.ts
@@ -65,20 +65,39 @@ async function createOrlistAllAttendees(
       throw new Error("Invalid request body", safe.error);
     }
     const bookingId = safe.data.bookingId;
-    delete safe.data.bookingId;
-    const noBookingId = safe.data;
-    const data = await prisma.attendee.create({
-      data: { ...noBookingId, booking: { connect: { id: parseInt(bookingId as string) } } },
+    const userId = await getCalcomUserId(res);
+    const userWithBookings = await prisma.user.findUnique({
+      where: { id: userId },
+      include: { bookings: true },
     });
-    const attendee = schemaAttendeePublic.parse(data);
+    if (!userWithBookings) {
+      throw new Error("User not found");
+    }
+    const userBookingIds = userWithBookings.bookings.map((booking: any) => booking.id).flat();
+    if (userBookingIds.includes(bookingId)) {
+      delete safe.data.bookingId;
+      const noBookingId = safe.data;
+      const data = await prisma.attendee.create({
+        data: {
+          ...noBookingId,
+          booking: { connect: { id: bookingId } },
+        },
+      });
+      const attendee = schemaAttendeePublic.parse(data);
 
-    if (attendee) res.status(201).json({ attendee, message: "Attendee created successfully" });
-    else
-      (error: Error) =>
-        res.status(400).json({
-          message: "Could not create new attendee",
-          error,
+      if (attendee) {
+        res.status(201).json({
+          attendee,
+          message: "Attendee created successfully",
         });
+      } else {
+        (error: Error) =>
+          res.status(400).json({
+            message: "Could not create new attendee",
+            error,
+          });
+      }
+    } else res.status(401).json({ message: "Unauthorized" });
   } else res.status(405).json({ message: `Method ${method} not allowed` });
 }
 
diff --git a/pages/api/availabilities/index.ts b/pages/api/availabilities/index.ts
index 425436bb14..45349b6b3f 100644
--- a/pages/api/availabilities/index.ts
+++ b/pages/api/availabilities/index.ts
@@ -55,7 +55,7 @@ async function createOrlistAllAvailabilities(
     const safe = schemaAvailabilityBodyParams.safeParse(req.body);
     if (!safe.success) throw new Error("Invalid request body");
 
-    const data = await prisma.availability.create({ data: safe.data });
+    const data = await prisma.availability.create({ data: { ...safe.data, userId } });
     const availability = schemaAvailabilityPublic.parse(data);
 
     if (availability) res.status(201).json({ availability, message: "Availability created successfully" });
diff --git a/pages/api/booking-references/[id].ts b/pages/api/booking-references/[id].ts
index 2fac6f79db..c9527e3f99 100644
--- a/pages/api/booking-references/[id].ts
+++ b/pages/api/booking-references/[id].ts
@@ -92,7 +92,6 @@ export async function bookingReferenceById(
   const safeQuery = schemaQueryIdParseInt.safeParse(query);
   const safeBody = schemaBookingReferenceBodyParams.safeParse(body);
   if (!safeQuery.success) throw new Error("Invalid request query", safeQuery.error);
-  // FIXME: Allow only userId owner of booking ref to edit it
   const userId = await getCalcomUserId(res);
   const userWithBookings = await prisma.user.findUnique({
     where: { id: userId },
@@ -100,7 +99,6 @@ export async function bookingReferenceById(
   });
   if (!userWithBookings) throw new Error("User not found");
   const userBookingIds = userWithBookings.bookings.map((booking: any) => booking.id).flat();
-  console.log(userBookingIds);
   const bookingReference = await prisma.bookingReference.findUnique({ where: { id: safeQuery.data.id } });
   if (!bookingReference) throw new Error("BookingReference not found");
   if (userBookingIds.includes(bookingReference.bookingId)) {
diff --git a/pages/api/bookings/[id].ts b/pages/api/bookings/[id].ts
index 45f24774e6..54e21b5109 100644
--- a/pages/api/bookings/[id].ts
+++ b/pages/api/bookings/[id].ts
@@ -4,6 +4,7 @@ import prisma from "@calcom/prisma";
 
 import { withMiddleware } from "@lib/helpers/withMiddleware";
 import type { BookingResponse } from "@lib/types";
+import { getCalcomUserId } from "@lib/utils/getCalcomUserId";
 import { schemaBookingBodyParams, schemaBookingPublic } from "@lib/validations/booking";
 import {
   schemaQueryIdParseInt,
@@ -84,47 +85,68 @@ export async function bookingById(req: NextApiRequest, res: NextApiResponse<Book
   const safeQuery = schemaQueryIdParseInt.safeParse(query);
   const safeBody = schemaBookingBodyParams.safeParse(body);
   if (!safeQuery.success) throw new Error("Invalid request query", safeQuery.error);
-  // FIXME: Allow only userId owner of booking to edit it
-  switch (method) {
-    case "GET":
-      await prisma.booking
-        .findUnique({ where: { id: safeQuery.data.id } })
-        .then((data) => schemaBookingPublic.parse(data))
-        .then((booking) => res.status(200).json({ booking }))
-        .catch((error: Error) =>
-          res.status(404).json({ message: `Booking with id: ${safeQuery.data.id} not found`, error })
-        );
-      break;
+  const userId = await getCalcomUserId(res);
+  const userWithBookings = await prisma.user.findUnique({
+    where: { id: userId },
+    include: { bookings: true },
+  });
+  if (!userWithBookings) throw new Error("User not found");
+  const userBookingIds = userWithBookings.bookings.map((booking: any) => booking.id).flat();
+  if (userBookingIds.includes(safeQuery.data.id)) {
+    switch (method) {
+      case "GET":
+        await prisma.booking
+          .findUnique({ where: { id: safeQuery.data.id } })
+          .then((data) => schemaBookingPublic.parse(data))
+          .then((booking) => res.status(200).json({ booking }))
+          .catch((error: Error) =>
+            res.status(404).json({
+              message: `Booking with id: ${safeQuery.data.id} not found`,
+              error,
+            })
+          );
+        break;
 
-    case "PATCH":
-      if (!safeBody.success) throw new Error("Invalid request body");
-      await prisma.booking
-        .update({
-          where: { id: safeQuery.data.id },
-          data: safeBody.data,
-        })
-        .then((data) => schemaBookingPublic.parse(data))
-        .then((booking) => res.status(200).json({ booking }))
-        .catch((error: Error) =>
-          res.status(404).json({ message: `Booking with id: ${safeQuery.data.id} not found`, error })
-        );
-      break;
+      case "PATCH":
+        if (!safeBody.success) {
+          throw new Error("Invalid request body");
+        }
+        await prisma.booking
+          .update({
+            where: { id: safeQuery.data.id },
+            data: safeBody.data,
+          })
+          .then((data) => schemaBookingPublic.parse(data))
+          .then((booking) => res.status(200).json({ booking }))
+          .catch((error: Error) =>
+            res.status(404).json({
+              message: `Booking with id: ${safeQuery.data.id} not found`,
+              error,
+            })
+          );
+        break;
 
-    case "DELETE":
-      await prisma.booking
-        .delete({ where: { id: safeQuery.data.id } })
-        .then(() =>
-          res.status(200).json({ message: `Booking with id: ${safeQuery.data.id} deleted successfully` })
-        )
-        .catch((error: Error) =>
-          res.status(404).json({ message: `Booking with id: ${safeQuery.data.id} not found`, error })
-        );
-      break;
+      case "DELETE":
+        await prisma.booking
+          .delete({ where: { id: safeQuery.data.id } })
+          .then(() =>
+            res.status(200).json({
+              message: `Booking with id: ${safeQuery.data.id} deleted successfully`,
+            })
+          )
+          .catch((error: Error) =>
+            res.status(404).json({
+              message: `Booking with id: ${safeQuery.data.id} not found`,
+              error,
+            })
+          );
+        break;
 
-    default:
-      res.status(405).json({ message: "Method not allowed" });
-      break;
-  }
+      default:
+        res.status(405).json({ message: "Method not allowed" });
+        break;
+    }
+  } else res.status(401).json({ message: "Unauthorized" });
 }
 
 export default withMiddleware("HTTP_GET_DELETE_PATCH")(withValidQueryIdTransformParseInt(bookingById));
diff --git a/pages/api/bookings/index.ts b/pages/api/bookings/index.ts
index fd5f8b19af..2b2b55bf21 100644
--- a/pages/api/bookings/index.ts
+++ b/pages/api/bookings/index.ts
@@ -4,6 +4,7 @@ import prisma from "@calcom/prisma";
 
 import { withMiddleware } from "@lib/helpers/withMiddleware";
 import { BookingResponse, BookingsResponse } from "@lib/types";
+import { getCalcomUserId } from "@lib/utils/getCalcomUserId";
 import { schemaBookingBodyParams, schemaBookingPublic, withValidBooking } from "@lib/validations/booking";
 
 /**
@@ -38,10 +39,10 @@ async function createOrlistAllBookings(
   res: NextApiResponse<BookingsResponse | BookingResponse>
 ) {
   const { method } = req;
-  // FIXME: List only bookings owner by userId
+  const userId = await getCalcomUserId(res);
 
   if (method === "GET") {
-    const data = await prisma.booking.findMany();
+    const data = await prisma.booking.findMany({ where: { userId } });
     const bookings = data.map((booking) => schemaBookingPublic.parse(booking));
     if (bookings) res.status(200).json({ bookings });
     else
@@ -54,7 +55,7 @@ async function createOrlistAllBookings(
     const safe = schemaBookingBodyParams.safeParse(req.body);
     if (!safe.success) throw new Error("Invalid request body");
 
-    const data = await prisma.booking.create({ data: safe.data });
+    const data = await prisma.booking.create({ data: { ...safe.data, userId } });
     const booking = schemaBookingPublic.parse(data);
 
     if (booking) res.status(201).json({ booking, message: "Booking created successfully" });