diff --git a/app/src/main/java/com/p_vacho/neat_calendar/activities/NotificationsActivity.kt b/app/src/main/java/com/p_vacho/neat_calendar/activities/NotificationsActivity.kt
index 8f1e6e6..6baa624 100644
--- a/app/src/main/java/com/p_vacho/neat_calendar/activities/NotificationsActivity.kt
+++ b/app/src/main/java/com/p_vacho/neat_calendar/activities/NotificationsActivity.kt
@@ -25,6 +25,8 @@ import org.json.JSONException
 import org.json.JSONObject
 import retrofit2.HttpException
 
+// TODO: Localize all strings
+
 class NotificationsActivity : AppCompatActivity() {
     private lateinit var rvNotifications: RecyclerView
     private lateinit var btnBack: ImageButton
@@ -90,7 +92,11 @@ class NotificationsActivity : AppCompatActivity() {
     }
 
     private fun getInvitationData(invitationId: String, rvPosition: Int): InvitationResponse? {
-        return invitations[invitationId]
+        val ret = invitations[invitationId]
+        if (ret == null) {
+            Log.w("NotificationsActivity", "NotificationAdapter requested unknown invitation: $invitationId")
+        }
+        return ret
     }
 
     private fun getUserData(userId: String, rvPosition: Int?): UserResponse? {
@@ -139,25 +145,39 @@ class NotificationsActivity : AppCompatActivity() {
                         Toast.makeText(this@NotificationsActivity, "Invitation accepted", Toast.LENGTH_SHORT).show()
 
                         // Also mark the notification as read after the interaction
-                        if (!notification.read) handleNotificationClick(notification, position, false)
-                    }
+                        if (!notification.read) {
+                            handleNotificationClick(notification, position, false)
+                        } else {
+                            // If the notification was unread, handleNotificationClick will have triggered this
+                            // but otherwise, we'll need to trigger an item update ourselves, to make sure that
+                            // the accept/decline buttons are removed
+                            rvNotifications.adapter!!.notifyItemChanged(position)
+                        }                    }
                 }
             }
             NotificationAdapter.Action.DECLINE -> {
                 lifecycleScope.launch(Dispatchers.IO) {
                     val invitationId = notification.data
-                    RetrofitClient.invitationService.declineInvitation(invitationId)
+                    invitations[invitationId] = RetrofitClient.invitationService.declineInvitation(invitationId)
 
                     withContext(Dispatchers.Main) {
                         Toast.makeText(this@NotificationsActivity, "Invitation declined", Toast.LENGTH_SHORT).show()
 
                         // Also mark the notification as read after the interaction
-                        if (!notification.read) handleNotificationClick(notification, position, false)
+                        if (!notification.read) {
+                            handleNotificationClick(notification, position, false)
+                        } else {
+                            // If the notification was unread, handleNotificationClick will have triggered this
+                            // but otherwise, we'll need to trigger an item update ourselves, to make sure that
+                            // the accept/decline buttons are removed
+                            rvNotifications.adapter!!.notifyItemChanged(position)
+                        }
                     }
                 }
             }
             NotificationAdapter.Action.VIEW_EVENT -> {
                 // TODO: Handle viewing the event
+                if (!notification.read) handleNotificationClick(notification, position, false)
             }
         }
     }
diff --git a/app/src/main/java/com/p_vacho/neat_calendar/adapters/NotificationAdapter.kt b/app/src/main/java/com/p_vacho/neat_calendar/adapters/NotificationAdapter.kt
index b37046f..26ed47a 100644
--- a/app/src/main/java/com/p_vacho/neat_calendar/adapters/NotificationAdapter.kt
+++ b/app/src/main/java/com/p_vacho/neat_calendar/adapters/NotificationAdapter.kt
@@ -14,6 +14,8 @@ import java.time.Duration
 import java.time.OffsetDateTime
 import java.time.format.DateTimeFormatter
 
+// TODO: Localize all strings
+
 class NotificationAdapter(
     private val notifications: MutableList<NotificationResponse>,
     private val onActionClick: (NotificationResponse, Action, Int) -> Unit,
@@ -88,33 +90,65 @@ class NotificationAdapter(
         val user = getUserData(usernameId, position)
         val username = user?.username ?: "Unknown User"
 
+        val statusSuffix = when (invitation.status) {
+            "accepted" -> " [already accepted]"
+            "declined" -> " [already declined]"
+            "pending" -> ""
+            else -> throw IllegalStateException("Unexpected invitation status: ${invitation.status} for invitation ID: ${invitation.id}")
+        }
+
         return when (notification.message) {
-            "new-invitation" -> "You have received an event invitation from @$username"
-            "invitation-accepted" -> "@$username has accepted your event invitation"
-            "invitation-declined" -> "@$username has declined your event invitation"
+            "new-invitation" -> "You have received an event invitation from @$username$statusSuffix"
+            "invitation-accepted" -> "@$username has accepted your event invitation$statusSuffix"
+            "invitation-declined" -> "@$username has declined your event invitation$statusSuffix"
             else -> throw IllegalArgumentException("Unexpected notification message: ${notification.message}")
         }
     }
 
+
     private fun handleInvitationActions(
         holder: NotificationViewHolder,
         notification: NotificationResponse,
         position: Int
     ) {
         if (notification.event_type == "invitation") {
+            val invitation = getInvitationData(notification.data, position)
+            if (invitation == null) {
+                // No buttons for deleted invitations
+                holder.invitationActions.visibility = View.GONE
+
+                return
+            }
+
             when (notification.message) {
                 "new-invitation" -> {
-                    // Show Accept/Decline & View buttons
-                    holder.invitationActions.visibility = View.VISIBLE
-                    holder.acceptButton.visibility = View.VISIBLE
-                    holder.declineButton.visibility = View.VISIBLE
-                    holder.viewEventButton.visibility = View.VISIBLE
+                    when (invitation.status) {
+                        "pending" -> {
+                            // Show Accept/Decline & View buttons
+                            holder.invitationActions.visibility = View.VISIBLE
+                            holder.acceptButton.visibility = View.VISIBLE
+                            holder.declineButton.visibility = View.VISIBLE
+                            holder.viewEventButton.visibility = View.VISIBLE
 
-                    holder.acceptButton.setOnClickListener {
-                        onActionClick(notification, Action.ACCEPT, position)
-                    }
-                    holder.declineButton.setOnClickListener {
-                        onActionClick(notification, Action.DECLINE, position)
+                            holder.acceptButton.setOnClickListener {
+                                onActionClick(notification, Action.ACCEPT, position)
+                            }
+                            holder.declineButton.setOnClickListener {
+                                onActionClick(notification, Action.DECLINE, position)
+                            }
+                        }
+                        "accepted", "declined" -> {
+                            // Show only View button
+                            holder.invitationActions.visibility = View.VISIBLE
+                            holder.acceptButton.visibility = View.GONE
+                            holder.declineButton.visibility = View.GONE
+                            holder.viewEventButton.visibility = View.VISIBLE
+
+                            holder.viewEventButton.setOnClickListener {
+                                onActionClick(notification, Action.VIEW_EVENT, position)
+                            }
+                        }
+                        else -> throw IllegalStateException("Unexpected invitation status: ${invitation.status} for invite ID: ${invitation.id}")
                     }
                 }
                 "invitation-accepted", "invitation-declined" -> {
diff --git a/app/src/main/java/com/p_vacho/neat_calendar/api/services/InvitationsService.kt b/app/src/main/java/com/p_vacho/neat_calendar/api/services/InvitationsService.kt
index 03c6f5f..951657d 100644
--- a/app/src/main/java/com/p_vacho/neat_calendar/api/services/InvitationsService.kt
+++ b/app/src/main/java/com/p_vacho/neat_calendar/api/services/InvitationsService.kt
@@ -21,9 +21,9 @@ interface InvitationsService {
     suspend fun getIncomingInvitations(@Path("user_id") userId: String): List<InvitationResponse>
 
     @POST("invitations/{invitation_id}/accept")
-    suspend fun acceptInvitation(@Path("invitation_id") invitationId: String): Unit
+    suspend fun acceptInvitation(@Path("invitation_id") invitationId: String): InvitationResponse
 
     @POST("invitations/{invitation_id}/decline")
-    suspend fun declineInvitation(@Path("invitation_id") invitationId: String): Unit
+    suspend fun declineInvitation(@Path("invitation_id") invitationId: String): InvitationResponse
 
 }
\ No newline at end of file