diff --git a/src/Umbraco.Core/Constants-ObjectTypes.cs b/src/Umbraco.Core/Constants-ObjectTypes.cs
index 4a79437c61..a1e6e55ee9 100644
--- a/src/Umbraco.Core/Constants-ObjectTypes.cs
+++ b/src/Umbraco.Core/Constants-ObjectTypes.cs
@@ -222,6 +222,16 @@ namespace Umbraco.Core
             /// Guid for a Forms DataSource.
             /// </summary>
             public static readonly Guid LanguageGuid = new Guid(Language);
+
+            /// <summary>
+            /// Guid for an Identifier Reservation.
+            /// </summary>
+            public const string IdReservation = "92849B1E-3904-4713-9356-F646F87C25F4";
+
+            /// <summary>
+            /// Guid for an Identifier Reservation.
+            /// </summary>
+            public static readonly Guid IdReservationGuid = new Guid(IdReservation);
         }
     }
 }
\ No newline at end of file
diff --git a/src/Umbraco.Core/Models/UmbracoObjectTypes.cs b/src/Umbraco.Core/Models/UmbracoObjectTypes.cs
index d0136a10a4..d4caaef768 100644
--- a/src/Umbraco.Core/Models/UmbracoObjectTypes.cs
+++ b/src/Umbraco.Core/Models/UmbracoObjectTypes.cs
@@ -185,6 +185,13 @@ namespace Umbraco.Core.Models
         /// </summary>
         [UmbracoObjectType(Constants.ObjectTypes.Language)]
         [FriendlyName("Language")]
-        Language
+        Language,
+
+        /// <summary>
+        /// Reserved Identifier
+        /// </summary>
+        [UmbracoObjectType(Constants.ObjectTypes.IdReservation)]
+        [FriendlyName("Identifier Reservation")]
+        IdReservation
     }
 }
\ No newline at end of file
diff --git a/src/Umbraco.Core/Persistence/Repositories/ContentRepository.cs b/src/Umbraco.Core/Persistence/Repositories/ContentRepository.cs
index eac9d197be..a01cbaa2e8 100644
--- a/src/Umbraco.Core/Persistence/Repositories/ContentRepository.cs
+++ b/src/Umbraco.Core/Persistence/Repositories/ContentRepository.cs
@@ -435,7 +435,24 @@ namespace Umbraco.Core.Persistence.Repositories
             nodeDto.Path = parent.Path;
             nodeDto.Level = short.Parse(level.ToString(CultureInfo.InvariantCulture));
             nodeDto.SortOrder = sortOrder;
-            var o = Database.IsNew(nodeDto) ? Convert.ToInt32(Database.Insert(nodeDto)) : Database.Update(nodeDto);
+
+            // note:
+            // there used to be a check on Database.IsNew(nodeDto) here to either Insert or Update,
+            // but I cannot figure out what was the point, as the node should obviously be new if
+            // we reach that point - removed.
+
+            // see if there's a reserved identifier for this unique id
+            var sql = new Sql("SELECT id FROM umbracoNode WHERE uniqueID=@0 AND nodeObjectType=@1", nodeDto.UniqueId, Constants.ObjectTypes.IdReservationGuid);
+            var id = Database.ExecuteScalar<int>(sql);
+            if (id > 0)
+            {
+                nodeDto.NodeId = id;
+                Database.Update(nodeDto);
+            }
+            else
+            {
+                Database.Insert(nodeDto);
+            }
 
             //Update with new correct path
             nodeDto.Path = string.Concat(parent.Path, ",", nodeDto.NodeId);
diff --git a/src/Umbraco.Core/Persistence/Repositories/MediaRepository.cs b/src/Umbraco.Core/Persistence/Repositories/MediaRepository.cs
index 598b16d78d..b22e8981b9 100644
--- a/src/Umbraco.Core/Persistence/Repositories/MediaRepository.cs
+++ b/src/Umbraco.Core/Persistence/Repositories/MediaRepository.cs
@@ -84,7 +84,7 @@ namespace Umbraco.Core.Persistence.Repositories
         #endregion
 
         #region Overrides of PetaPocoRepositoryBase<int,IMedia>
-        
+
         protected override Sql GetBaseQuery(BaseQueryType queryType)
         {
             var sql = new Sql();
@@ -153,7 +153,7 @@ namespace Umbraco.Core.Persistence.Repositories
         /// This is the underlying method that processes most queries for this repository
         /// </summary>
         /// <param name="sqlFull">
-        /// The full SQL to select all media data 
+        /// The full SQL to select all media data
         /// </param>
         /// <param name="pagingSqlQuery">
         /// The Id SQL to just return all media ids - used to process the properties for the media item
@@ -164,7 +164,7 @@ namespace Umbraco.Core.Persistence.Repositories
         {
             // fetch returns a list so it's ok to iterate it in this method
             var dtos = Database.Fetch<ContentVersionDto, ContentDto, NodeDto>(sqlFull);
-            
+
             //This is a tuple list identifying if the content item came from the cache or not
             var content = new List<Tuple<IMedia, bool>>();
             var defs = new DocumentDefinitionCollection();
@@ -180,7 +180,7 @@ namespace Umbraco.Core.Persistence.Repositories
                 if (withCache)
                 {
                     var cached = IsolatedCache.GetCacheItem<IMedia>(GetCacheIdKey<IMedia>(dto.NodeId));
-                    //only use this cached version if the dto returned is the same version - this is just a safety check, media doesn't 
+                    //only use this cached version if the dto returned is the same version - this is just a safety check, media doesn't
                     //store different versions, but just in case someone corrupts some data we'll double check to be sure.
                     if (cached != null && cached.Version == dto.VersionId)
                     {
@@ -303,7 +303,7 @@ namespace Umbraco.Core.Persistence.Repositories
                 .From<ContentXmlDto>(SqlSyntax)
                 .InnerJoin<NodeDto>(SqlSyntax)
                 .On<ContentXmlDto, NodeDto>(SqlSyntax, left => left.NodeId, right => right.NodeId);
-                
+
             if (contentTypeIdsA.Length > 0)
             {
                 xmlIdsQuery.InnerJoin<ContentDto>(SqlSyntax)
@@ -314,7 +314,7 @@ namespace Umbraco.Core.Persistence.Repositories
             }
 
             xmlIdsQuery.Where<NodeDto>(dto => dto.NodeObjectType == mediaObjectType, SqlSyntax);
-            
+
             var allXmlIds = Database.Fetch<int>(xmlIdsQuery);
 
             var toRemove = allXmlIds.Except(allMediaIds).ToArray();
@@ -380,7 +380,24 @@ namespace Umbraco.Core.Persistence.Repositories
             nodeDto.Path = parent.Path;
             nodeDto.Level = short.Parse(level.ToString(CultureInfo.InvariantCulture));
             nodeDto.SortOrder = sortOrder;
-            var o = Database.IsNew(nodeDto) ? Convert.ToInt32(Database.Insert(nodeDto)) : Database.Update(nodeDto);
+
+            // note:
+            // there used to be a check on Database.IsNew(nodeDto) here to either Insert or Update,
+            // but I cannot figure out what was the point, as the node should obviously be new if
+            // we reach that point - removed.
+
+            // see if there's a reserved identifier for this unique id
+            var sql = new Sql("SELECT id FROM umbracoNode WHERE uniqueID=@0 AND nodeObjectType=@1", nodeDto.UniqueId, Constants.ObjectTypes.IdReservationGuid);
+            var id = Database.ExecuteScalar<int>(sql);
+            if (id > 0)
+            {
+                nodeDto.NodeId = id;
+                Database.Update(nodeDto);
+            }
+            else
+            {
+                Database.Insert(nodeDto);
+            }
 
             //Update with new correct path
             nodeDto.Path = string.Concat(parent.Path, ",", nodeDto.NodeId);
@@ -564,7 +581,7 @@ namespace Umbraco.Core.Persistence.Repositories
         private IMedia CreateMediaFromDto(ContentVersionDto dto, Sql docSql)
         {
             var contentType = _mediaTypeRepository.Get(dto.ContentDto.ContentTypeId);
-            
+
             var media = MediaFactory.BuildEntity(dto, contentType);
 
             var docDef = new DocumentDefinition(dto, contentType);
@@ -584,7 +601,7 @@ namespace Umbraco.Core.Persistence.Repositories
             if (EnsureUniqueNaming == false)
                 return nodeName;
 
-            var names = Database.Fetch<SimilarNodeName>("SELECT id, text AS name FROM umbracoNode WHERE nodeObjectType=@objectType AND parentId=@parentId", 
+            var names = Database.Fetch<SimilarNodeName>("SELECT id, text AS name FROM umbracoNode WHERE nodeObjectType=@objectType AND parentId=@parentId",
                 new { objectType = NodeObjectTypeId, parentId });
 
             return SimilarNodeName.GetUniqueName(names, id, nodeName);
diff --git a/src/Umbraco.Core/Services/EntityService.cs b/src/Umbraco.Core/Services/EntityService.cs
index 04d6c276b2..c10311dc01 100644
--- a/src/Umbraco.Core/Services/EntityService.cs
+++ b/src/Umbraco.Core/Services/EntityService.cs
@@ -646,5 +646,34 @@ namespace Umbraco.Core.Services
                 return exists;
             }
         }
+
+        /// <inheritdoc />
+        public int ReserveId(Guid key)
+        {
+            NodeDto node;
+            using (var scope = UowProvider.ScopeProvider.CreateScope())
+            {
+                var sql = new Sql("SELECT * FROM umbracoNode WHERE uniqueID=@0 AND nodeObjectType=@1", key, Constants.ObjectTypes.IdReservationGuid);
+                node = scope.Database.SingleOrDefault<NodeDto>(sql);
+                if (node != null) throw new InvalidOperationException("An identifier has already been reserved for this Udi.");
+                node = new NodeDto
+                {
+                    UniqueId = key,
+                    Text = "RESERVED.ID",
+                    NodeObjectType = Constants.ObjectTypes.IdReservationGuid,
+
+                    CreateDate = DateTime.Now,
+                    UserId = 0,
+                    ParentId = -1,
+                    Level = 1,
+                    Path = "-1",
+                    SortOrder = 0,
+                    Trashed = false
+                };
+                scope.Database.Insert(node);
+                scope.Complete();
+            }
+            return node.NodeId;
+        }
     }
 }
\ No newline at end of file
diff --git a/src/Umbraco.Core/Services/IEntityService.cs b/src/Umbraco.Core/Services/IEntityService.cs
index 82e5227cf2..d1da84a1c8 100644
--- a/src/Umbraco.Core/Services/IEntityService.cs
+++ b/src/Umbraco.Core/Services/IEntityService.cs
@@ -170,7 +170,7 @@ namespace Umbraco.Core.Services
         /// <param name="totalRecords"></param>
         /// <param name="orderBy"></param>
         /// <param name="orderDirection"></param>
-        /// <param name="filter"></param>        
+        /// <param name="filter"></param>
         /// <returns></returns>
         IEnumerable<IUmbracoEntity> GetPagedDescendants(int id, UmbracoObjectTypes umbracoObjectType, long pageIndex, int pageSize, out long totalRecords,
             string orderBy = "path", Direction orderDirection = Direction.Ascending, string filter = "");
@@ -270,5 +270,13 @@ namespace Umbraco.Core.Services
         /// <param name="umbracoObjectType"><see cref="UmbracoObjectTypes"/></param>
         /// <returns>Type of the entity</returns>
         Type GetEntityType(UmbracoObjectTypes umbracoObjectType);
+
+        /// <summary>
+        /// Reserves an identifier for a key.
+        /// </summary>
+        /// <param name="key">They key.</param>
+        /// <returns>The identifier.</returns>
+        /// <remarks>When a new content or a media is saved with the key, it will have the reserved identifier.</remarks>
+        int ReserveId(Guid key);
     }
 }
\ No newline at end of file
diff --git a/src/Umbraco.Core/Services/IdkMap.cs b/src/Umbraco.Core/Services/IdkMap.cs
index 015bb104dc..411316fca2 100644
--- a/src/Umbraco.Core/Services/IdkMap.cs
+++ b/src/Umbraco.Core/Services/IdkMap.cs
@@ -46,6 +46,10 @@ namespace Umbraco.Core.Services
 
             if (val == null) return Attempt<int>.Fail();
 
+            // cache reservations, when something is saved this cache is cleared anyways
+            //if (umbracoObjectType == UmbracoObjectTypes.IdReservation)
+            //    Attempt.Succeed(val.Value);
+
             try
             {
                 _locker.EnterWriteLock();
@@ -95,6 +99,10 @@ namespace Umbraco.Core.Services
 
             if (val == null) return Attempt<Guid>.Fail();
 
+            // cache reservations, when something is saved this cache is cleared anyways
+            //if (umbracoObjectType == UmbracoObjectTypes.IdReservation)
+            //    Attempt.Succeed(val.Value);
+
             try
             {
                 _locker.EnterWriteLock();