diff --git a/src/main/java/kamkeel/npcs/controllers/ProfileController.java b/src/main/java/kamkeel/npcs/controllers/ProfileController.java
index 96ee90145..f9367dfac 100644
--- a/src/main/java/kamkeel/npcs/controllers/ProfileController.java
+++ b/src/main/java/kamkeel/npcs/controllers/ProfileController.java
@@ -22,8 +22,7 @@ import java.io.InputStreamReader;
 import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.URL;
-import java.util.HashMap;
-import java.util.UUID;
+import java.util.*;
 
 public class ProfileController {
 
@@ -234,6 +233,19 @@ public class ProfileController {
             LogWriter.error("Profile is locked; cannot clone slot.");
             return ProfileOperation.LOCKED;
         }
+
+        // Run verification checks on all IProfileData in priority order.
+        if(profile.player != null) {
+            List<IProfileData> dataList = new ArrayList<>(profileTypes.values());
+            dataList.sort(Comparator.comparingInt(IProfileData::getSwitchPriority));
+            for(IProfileData pd : dataList) {
+                if(!pd.verifySwitch(profile.player)) {
+                    LogWriter.error("Verification check failed for profile type: " + pd.getTagName());
+                    return ProfileOperation.VERIFICATION_FAILED;
+                }
+            }
+        }
+
         if(!profile.slots.containsKey(sourceSlotId)) {
             LogWriter.error("Source slot " + sourceSlotId + " does not exist.");
             return ProfileOperation.ERROR;
@@ -442,14 +454,16 @@ public class ProfileController {
             dataCompound = new NBTTagCompound();
             slot.setCompound(dataCompound);
         }
-        for(IProfileData profileData : profileTypes.values()){
+
+        List<IProfileData> dataList = new ArrayList<>(profileTypes.values());
+        dataList.sort(Comparator.comparingInt(IProfileData::getSwitchPriority));
+        for(IProfileData profileData : dataList){
             NBTTagCompound cloned = (NBTTagCompound) profileData.getCurrentNBT(player).copy();
             dataCompound.setTag(profileData.getTagName(), cloned);
         }
         slot.setCompound(dataCompound);
     }
 
-    // TODO:
     public static void loadSlotData(EntityPlayer player) {
         if(player == null || !activeProfiles.containsKey(player.getUniqueID()))
             return;
@@ -462,7 +476,9 @@ public class ProfileController {
         NBTTagCompound slotCompound = (NBTTagCompound) profile.slots.get(profile.currentID).getCompound().copy();
 
         // For each registered profile data type, load its saved compound onto the player.
-        for(IProfileData profileData : profileTypes.values()){
+        List<IProfileData> dataList = new ArrayList<>(profileTypes.values());
+        dataList.sort(Comparator.comparingInt(IProfileData::getSwitchPriority));
+        for(IProfileData profileData : dataList){
             NBTTagCompound data;
             if(slotCompound.hasKey(profileData.getTagName()))
                 data = slotCompound.getCompoundTag(profileData.getTagName());
@@ -470,6 +486,9 @@ public class ProfileController {
                 data = new NBTTagCompound();
 
             profileData.setNBT(player, data);
+        }
+
+        for(IProfileData profileData : dataList){
             profileData.save(player);
         }
     }
diff --git a/src/main/java/kamkeel/npcs/controllers/data/CNPCData.java b/src/main/java/kamkeel/npcs/controllers/data/CNPCData.java
index d4e61530f..8662e0b84 100644
--- a/src/main/java/kamkeel/npcs/controllers/data/CNPCData.java
+++ b/src/main/java/kamkeel/npcs/controllers/data/CNPCData.java
@@ -33,10 +33,19 @@ public class CNPCData implements IProfileData {
             PlayerData newData = new PlayerData();
             newData.player = player;
             customNPCData.setNBT((NBTTagCompound) newData.getNBT().copy());
-        }
-        else {
+        } else {
             customNPCData.setNBT(replace);
         }
         customNPCData.updateClient = true;
     }
+
+    @Override
+    public int getSwitchPriority() {
+        return 0;
+    }
+
+    @Override
+    public boolean verifySwitch(EntityPlayer player) {
+        return true;
+    }
 }
diff --git a/src/main/java/kamkeel/npcs/controllers/data/IProfileData.java b/src/main/java/kamkeel/npcs/controllers/data/IProfileData.java
index a68abc597..853ddf1e0 100644
--- a/src/main/java/kamkeel/npcs/controllers/data/IProfileData.java
+++ b/src/main/java/kamkeel/npcs/controllers/data/IProfileData.java
@@ -6,24 +6,37 @@ import net.minecraft.nbt.NBTTagCompound;
 public interface IProfileData {
 
     /**
-     * Do not use the tag: - Name, lastLoaded, ID
+     * Do not use the tags: Name, lastLoaded, ID.
      *
-     * @return The Save Tag utilized in the Profile
+     * @return The save tag utilized in the Profile.
      */
     public String getTagName();
 
     /**
-     * @return NBTTagCompound of their Current Data for a given Entity Player
+     * @return NBTTagCompound of the current data for a given EntityPlayer.
      */
     public NBTTagCompound getCurrentNBT(EntityPlayer player);
 
     /**
-     * Called immediately after setNBT() Replaces existing NBT
+     * Called immediately after setNBT() to replace existing NBT.
      */
     public void save(EntityPlayer player);
 
     /**
-     * Replaces their Current Data operation when changing Profiles
+     * Replaces the current data operation when changing profiles.
      */
     public void setNBT(EntityPlayer player, NBTTagCompound replace);
+
+    /**
+     * Returns the priority for this ProfileData's verification check.
+     * Lower numbers run first.
+     */
+    public int getSwitchPriority();
+
+    /**
+     * Called before a profile switch occurs.
+     * @param player The player switching profiles.
+     * @return true if allowed, false if not.
+     */
+    public boolean verifySwitch(EntityPlayer player);
 }
diff --git a/src/main/java/kamkeel/npcs/controllers/data/ProfileOperation.java b/src/main/java/kamkeel/npcs/controllers/data/ProfileOperation.java
index 62ec9508a..f3d6d1179 100644
--- a/src/main/java/kamkeel/npcs/controllers/data/ProfileOperation.java
+++ b/src/main/java/kamkeel/npcs/controllers/data/ProfileOperation.java
@@ -4,5 +4,7 @@ public enum ProfileOperation {
     SUCCESS,
     ERROR,
     LOCKED,
-    PLAYER_NOT_FOUND
+    PLAYER_NOT_FOUND,
+    VERIFICATION_FAILED
 }
+