diff --git a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/MemberPriceModal/index.tsx b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/MemberPriceModal/index.tsx
index 0bad80707..097496df0 100644
--- a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/MemberPriceModal/index.tsx
+++ b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/MemberPriceModal/index.tsx
@@ -1,5 +1,7 @@
 "use client"
 
+import { useEffect, useState } from "react"
+import { useFormContext, useWatch } from "react-hook-form"
 import { useIntl } from "react-intl"
 
 import MagicWandIcon from "@scandic-hotels/design-system/Icons/MagicWandIcon"
@@ -14,20 +16,35 @@ import { formatPrice } from "@/utils/numberFormatting"
 
 import styles from "./modal.module.css"
 
-import type { Dispatch, SetStateAction } from "react"
-
 import { CurrencyEnum } from "@/types/enums/currency"
 
-export default function MemberPriceModal({
-  isOpen,
-  setIsOpen,
-}: {
-  isOpen: boolean
-  setIsOpen: Dispatch<SetStateAction<boolean>>
-}) {
-  const { room } = useRoomContext()
+export default function MemberPriceModal() {
+  const {
+    actions: { updatePriceForMembershipNo },
+    room,
+  } = useRoomContext()
   const memberRate = "member" in room.roomRate ? room.roomRate.member : null
   const intl = useIntl()
+  const [isOpen, setIsOpen] = useState(false)
+  const { getFieldState, trigger } = useFormContext()
+
+  const [join, membershipNo] = useWatch({ name: ["join", "membershipNo"] })
+
+  useEffect(() => {
+    if (join) {
+      setIsOpen(true)
+    }
+  }, [join])
+
+  useEffect(() => {
+    trigger("membershipNo").then((isValid) => {
+      const { isDirty } = getFieldState("membershipNo")
+      updatePriceForMembershipNo(membershipNo, isValid)
+      if (isValid && isDirty) {
+        setIsOpen(true)
+      }
+    })
+  }, [getFieldState, membershipNo, trigger, updatePriceForMembershipNo])
 
   if (!memberRate) {
     return null
@@ -36,7 +53,7 @@ export default function MemberPriceModal({
   const memberPrice = memberRate?.localPrice ?? memberRate?.requestedPrice
 
   return (
-    <Modal isOpen={isOpen} onToggle={setIsOpen}>
+    <Modal isOpen={isOpen} onToggle={() => setIsOpen(false)}>
       <div className={styles.modalContent}>
         <div className={styles.innerModalContent}>
           <MagicWandIcon width="265px" />
diff --git a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/Multiroom/JoinScandicFriendsCard/index.tsx b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/Multiroom/JoinScandicFriendsCard/index.tsx
index 3983e6b1f..a85ba9350 100644
--- a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/Multiroom/JoinScandicFriendsCard/index.tsx
+++ b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/Multiroom/JoinScandicFriendsCard/index.tsx
@@ -1,6 +1,5 @@
 "use client"
 
-import { useState } from "react"
 import { useIntl } from "react-intl"
 
 import { MaterialIcon } from "@scandic-hotels/design-system/Icons/MaterialIcon"
@@ -10,8 +9,6 @@ import Caption from "@/components/TempDesignSystem/Text/Caption"
 import { useRoomContext } from "@/contexts/Details/Room"
 import { formatPrice } from "@/utils/numberFormatting"
 
-import MemberPriceModal from "../../MemberPriceModal"
-
 import styles from "./joinScandicFriendsCard.module.css"
 
 import type { JoinScandicFriendsCardProps } from "@/types/components/hotelReservation/enterDetails/details"
@@ -26,13 +23,9 @@ export default function JoinScandicFriendsCard({
     roomNr,
     actions: { updateJoin },
   } = useRoomContext()
-  const [isMemberPriceModalOpen, setIsMemberPriceModalOpen] = useState(false)
 
   function onChange(event: { target: { value: boolean } }) {
     updateJoin(event.target.value)
-    if (event.target.value) {
-      setIsMemberPriceModalOpen(true)
-    }
   }
 
   if (!("member" in room.roomRate) || !room.roomRate.member) {
@@ -106,10 +99,6 @@ export default function JoinScandicFriendsCard({
           </Caption>
         ))}
       </div>
-      <MemberPriceModal
-        isOpen={isMemberPriceModalOpen}
-        setIsOpen={setIsMemberPriceModalOpen}
-      />
     </div>
   )
 }
diff --git a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/Multiroom/index.tsx b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/Multiroom/index.tsx
index 6012464c7..650036461 100644
--- a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/Multiroom/index.tsx
+++ b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/Multiroom/index.tsx
@@ -13,6 +13,7 @@ import Phone from "@/components/TempDesignSystem/Form/Phone"
 import Footnote from "@/components/TempDesignSystem/Text/Footnote"
 import { useRoomContext } from "@/contexts/Details/Room"
 
+import MemberPriceModal from "../MemberPriceModal"
 import JoinScandicFriendsCard from "./JoinScandicFriendsCard"
 import { getMultiroomDetailsSchema } from "./schema"
 
@@ -52,11 +53,7 @@ export default function Details() {
   )
 
   const methods = useForm({
-    criteriaMode: "all",
-    mode: "all",
-    resolver: zodResolver(getMultiroomDetailsSchema(crossValidationData)),
-    reValidateMode: "onChange",
-    values: {
+    defaultValues: {
       countryCode: initialData.countryCode,
       email: initialData.email,
       firstName: initialData.firstName,
@@ -68,6 +65,10 @@ export default function Details() {
         comment: room.specialRequest.comment,
       },
     },
+    criteriaMode: "all",
+    mode: "all",
+    resolver: zodResolver(getMultiroomDetailsSchema(crossValidationData)),
+    reValidateMode: "onChange",
   })
 
   const {
@@ -189,6 +190,7 @@ export default function Details() {
           )}
           <SpecialRequests registerOptions={{ onBlur: updateDetailsStore }} />
         </div>
+        <MemberPriceModal />
       </form>
     </FormProvider>
   )
diff --git a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/RoomOne/JoinScandicFriendsCard/index.tsx b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/RoomOne/JoinScandicFriendsCard/index.tsx
index 06348d850..5207f6970 100644
--- a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/RoomOne/JoinScandicFriendsCard/index.tsx
+++ b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/RoomOne/JoinScandicFriendsCard/index.tsx
@@ -1,6 +1,4 @@
 "use client"
-
-import { useState } from "react"
 import { useIntl } from "react-intl"
 
 import { MaterialIcon } from "@scandic-hotels/design-system/Icons/MaterialIcon"
@@ -16,8 +14,6 @@ import { useRoomContext } from "@/contexts/Details/Room"
 import useLang from "@/hooks/useLang"
 import { formatPrice } from "@/utils/numberFormatting"
 
-import MemberPriceModal from "../../MemberPriceModal"
-
 import styles from "./joinScandicFriendsCard.module.css"
 
 import type { JoinScandicFriendsCardProps } from "@/types/components/hotelReservation/enterDetails/details"
@@ -32,13 +28,9 @@ export default function JoinScandicFriendsCard({
     room,
     actions: { updateJoin },
   } = useRoomContext()
-  const [isMemberPriceModalOpen, setIsMemberPriceModalOpen] = useState(false)
 
   function onChange(event: { target: { value: boolean } }) {
     updateJoin(event.target.value)
-    if (event.target.value) {
-      setIsMemberPriceModalOpen(true)
-    }
   }
 
   if (!("member" in room.roomRate) || !room.roomRate.member) {
@@ -156,10 +148,6 @@ export default function JoinScandicFriendsCard({
           )}
         </Footnote>
       </div>
-      <MemberPriceModal
-        isOpen={isMemberPriceModalOpen}
-        setIsOpen={setIsMemberPriceModalOpen}
-      />
     </div>
   )
 }
diff --git a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/RoomOne/index.tsx b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/RoomOne/index.tsx
index 367bbe0bf..37bebc659 100644
--- a/apps/scandic-web/components/HotelReservation/EnterDetails/Details/RoomOne/index.tsx
+++ b/apps/scandic-web/components/HotelReservation/EnterDetails/Details/RoomOne/index.tsx
@@ -13,6 +13,7 @@ import Phone from "@/components/TempDesignSystem/Form/Phone"
 import Footnote from "@/components/TempDesignSystem/Text/Footnote"
 import { useRoomContext } from "@/contexts/Details/Room"
 
+import MemberPriceModal from "../MemberPriceModal"
 import JoinScandicFriendsCard from "./JoinScandicFriendsCard"
 import { guestDetailsSchema, signedInDetailsSchema } from "./schema"
 import Signup from "./Signup"
@@ -43,25 +44,25 @@ export default function Details({ user }: DetailsProps) {
   const memberRate = "member" in room.roomRate ? room.roomRate.member : null
 
   const methods = useForm({
-    criteriaMode: "all",
-    mode: "all",
-    resolver: zodResolver(user ? signedInDetailsSchema : guestDetailsSchema),
-    reValidateMode: "onChange",
-    values: {
-      countryCode: user?.address?.countryCode ?? initialData.countryCode,
+    defaultValues: {
+      countryCode: user?.address?.countryCode || initialData.countryCode,
       dateOfBirth:
         "dateOfBirth" in initialData ? initialData.dateOfBirth : undefined,
-      email: user?.email ?? initialData.email,
-      firstName: user?.firstName ?? initialData.firstName,
+      email: user?.email || initialData.email,
+      firstName: user?.firstName || initialData.firstName,
       join: initialData.join,
-      lastName: user?.lastName ?? initialData.lastName,
+      lastName: user?.lastName || initialData.lastName,
       membershipNo: initialData.membershipNo,
-      phoneNumber: user?.phoneNumber ?? initialData.phoneNumber,
+      phoneNumber: user?.phoneNumber || initialData.phoneNumber,
       zipCode: "zipCode" in initialData ? initialData.zipCode : undefined,
       specialRequest: {
         comment: room.specialRequest.comment,
       },
     },
+    criteriaMode: "all",
+    mode: "all",
+    resolver: zodResolver(user ? signedInDetailsSchema : guestDetailsSchema),
+    reValidateMode: "onChange",
   })
 
   const {
@@ -168,6 +169,7 @@ export default function Details({ user }: DetailsProps) {
           )}
           <SpecialRequests registerOptions={{ onBlur: updateDetailsStore }} />
         </div>
+        <MemberPriceModal />
       </form>
     </FormProvider>
   )
diff --git a/apps/scandic-web/components/TempDesignSystem/Form/Phone/index.tsx b/apps/scandic-web/components/TempDesignSystem/Form/Phone/index.tsx
index cb7e18f8b..f6021b64c 100644
--- a/apps/scandic-web/components/TempDesignSystem/Form/Phone/index.tsx
+++ b/apps/scandic-web/components/TempDesignSystem/Form/Phone/index.tsx
@@ -57,7 +57,7 @@ export default function Phone({
     rules: registerOptions,
   })
 
-  const defaultPhoneNumber = formState.defaultValues?.phoneNumber
+  const defaultPhoneNumber = formState.defaultValues?.phoneNumber ?? ""
 
   // If defaultPhoneNumber exists and is valid, parse it to get the country code,
   // otherwise set the default country from the lang.
diff --git a/apps/scandic-web/providers/EnterDetailsProvider.tsx b/apps/scandic-web/providers/EnterDetailsProvider.tsx
index 009e1b08a..f86b27773 100644
--- a/apps/scandic-web/providers/EnterDetailsProvider.tsx
+++ b/apps/scandic-web/providers/EnterDetailsProvider.tsx
@@ -1,6 +1,6 @@
 "use client"
 import deepmerge from "deepmerge"
-import { useEffect, useRef } from "react"
+import { useEffect, useRef, useState } from "react"
 
 import { dt } from "@/lib/dt"
 import { createDetailsStore } from "@/stores/enter-details"
@@ -14,6 +14,7 @@ import {
 
 import { getMultiroomDetailsSchema } from "@/components/HotelReservation/EnterDetails/Details/Multiroom/schema"
 import { guestDetailsSchema } from "@/components/HotelReservation/EnterDetails/Details/RoomOne/schema"
+import LoadingSpinner from "@/components/LoadingSpinner"
 import { DetailsContext } from "@/contexts/Details"
 
 import type { DetailsStore } from "@/types/contexts/enter-details"
@@ -31,6 +32,11 @@ export default function EnterDetailsProvider({
   user,
   vat,
 }: DetailsProviderProps) {
+  // This state is needed to be able to use defaultValues for
+  // react-hook-form since values needs to be there on mount
+  // and since we read from SessionStorage we need to delay
+  // rendering the form until that has been done.
+  const [hasInitializedStore, setHasInitializedStore] = useState(false)
   const storeRef = useRef<DetailsStore>()
   if (!storeRef.current) {
     const initialData: InitialState = {
@@ -74,16 +80,19 @@ export default function EnterDetailsProvider({
   useEffect(() => {
     const storedValues = readFromSessionStorage()
     if (!storedValues) {
+      setHasInitializedStore(true)
       return
     }
     const isSameBooking = checkIsSameBooking(storedValues.booking, booking)
     if (!isSameBooking) {
       clearSessionStorage()
+      setHasInitializedStore(true)
       return
     }
 
     const store = storeRef.current?.getState()
     if (!store) {
+      setHasInitializedStore(true)
       return
     }
 
@@ -209,11 +218,13 @@ export default function EnterDetailsProvider({
       rooms: filteredOutMissingRooms,
       totalPrice,
     })
+
+    setHasInitializedStore(true)
   }, [booking, rooms, user])
 
   return (
     <DetailsContext.Provider value={storeRef.current}>
-      {children}
+      {hasInitializedStore ? children : <LoadingSpinner fullPage />}
     </DetailsContext.Provider>
   )
 }
diff --git a/apps/scandic-web/stores/enter-details/index.ts b/apps/scandic-web/stores/enter-details/index.ts
index 14e9efaee..921fda158 100644
--- a/apps/scandic-web/stores/enter-details/index.ts
+++ b/apps/scandic-web/stores/enter-details/index.ts
@@ -253,24 +253,18 @@ export function createDetailsStore(
               })
             )
           },
-          updateJoin(join) {
+          updatePriceForMembershipNo(membershipNo, isValid) {
             return set(
               produce((state: DetailsState) => {
                 const currentRoom = state.rooms[idx].room
 
-                currentRoom.guest.join = join
-
-                if (join) {
-                  currentRoom.guest.membershipNo = undefined
-                }
+                currentRoom.guest.join = false
+                currentRoom.guest.membershipNo = isValid ? membershipNo : ""
 
+                const isValidMembershipNo = isValid && !!membershipNo
                 currentRoom.roomPrice = getRoomPrice(
                   currentRoom.roomRate,
-                  Boolean(
-                    join ||
-                      currentRoom.guest.membershipNo ||
-                      (idx === 0 && isMember)
-                  )
+                  isValidMembershipNo
                 )
 
                 const nights = dt(state.booking.toDate).diff(
@@ -284,6 +278,43 @@ export function createDetailsStore(
                   isMember,
                   nights
                 )
+
+                writeToSessionStorage({
+                  booking: state.booking,
+                  rooms: state.rooms,
+                })
+              })
+            )
+          },
+          updateJoin(join) {
+            return set(
+              produce((state: DetailsState) => {
+                const currentRoom = state.rooms[idx].room
+
+                currentRoom.guest.join = join
+
+                if (join) {
+                  currentRoom.guest.membershipNo = ""
+                }
+
+                currentRoom.roomPrice = getRoomPrice(currentRoom.roomRate, join)
+
+                const nights = dt(state.booking.toDate).diff(
+                  state.booking.fromDate,
+                  "days"
+                )
+
+                state.totalPrice = calcTotalPrice(
+                  state.rooms,
+                  state.totalPrice.local.currency,
+                  isMember,
+                  nights
+                )
+
+                writeToSessionStorage({
+                  booking: state.booking,
+                  rooms: state.rooms,
+                })
               })
             )
           },
diff --git a/apps/scandic-web/types/contexts/details/room.ts b/apps/scandic-web/types/contexts/details/room.ts
index f0cb273fe..b016baba3 100644
--- a/apps/scandic-web/types/contexts/details/room.ts
+++ b/apps/scandic-web/types/contexts/details/room.ts
@@ -1,16 +1,7 @@
-import type { BreakfastPackage } from "@/types/components/hotelReservation/breakfast"
-import type { BedTypeSchema } from "@/types/components/hotelReservation/enterDetails/bedType"
-import type { DetailsSchema } from "@/types/components/hotelReservation/enterDetails/details"
 import type { RoomState } from "@/types/stores/enter-details"
 
 export interface RoomContextValue {
-  actions: {
-    setIncomplete: () => void
-    updateBedType: (data: BedTypeSchema) => void
-    updateBreakfast: (data: BreakfastPackage | false) => void
-    updateJoin: (join: boolean) => void
-    updateDetails: (data: DetailsSchema) => void
-  }
+  actions: RoomState["actions"]
   isComplete: RoomState["isComplete"]
   idx: number
   room: RoomState["room"]
diff --git a/apps/scandic-web/types/stores/enter-details.ts b/apps/scandic-web/types/stores/enter-details.ts
index 897638d11..cf16821c4 100644
--- a/apps/scandic-web/types/stores/enter-details.ts
+++ b/apps/scandic-web/types/stores/enter-details.ts
@@ -65,6 +65,7 @@ export interface RoomState {
     updateBedType: (data: BedTypeSchema) => void
     updateBreakfast: (data: BreakfastPackage | false) => void
     updateJoin: (join: boolean) => void
+    updatePriceForMembershipNo: (membershipNo: string, isValid: boolean) => void
     updateDetails: (data: DetailsSchema) => void
   }
   isComplete: boolean