diff --git a/eeschema/dialogs/dialog_sheet_properties.cpp b/eeschema/dialogs/dialog_sheet_properties.cpp
index cc2d5b8cd0..d8c92b6363 100644
--- a/eeschema/dialogs/dialog_sheet_properties.cpp
+++ b/eeschema/dialogs/dialog_sheet_properties.cpp
@@ -165,7 +165,7 @@ bool DIALOG_SHEET_PROPERTIES::TransferDataToWindow()
 
     instance.push_back( m_sheet );
 
-    wxString nextPageNumber = m_sheet->GetPageNumber( instance );
+    wxString nextPageNumber = m_sheet->GetPageNumber();
 
     m_pageNumberTextCtrl->ChangeValue( nextPageNumber );
 
@@ -373,10 +373,7 @@ bool DIALOG_SHEET_PROPERTIES::TransferDataFromWindow()
 
     instance.push_back( m_sheet );
 
-    if( m_sheet->IsNew() )
-        m_sheet->AddInstance( instance.Path() );
-
-    m_sheet->SetPageNumber( instance, m_pageNumberTextCtrl->GetValue() );
+    m_sheet->SetPageNumber( m_pageNumberTextCtrl->GetValue() );
 
     m_frame->TestDanglingEnds();
 
diff --git a/eeschema/hierarch.cpp b/eeschema/hierarch.cpp
index 4267e136bf..e82d88abcd 100644
--- a/eeschema/hierarch.cpp
+++ b/eeschema/hierarch.cpp
@@ -179,10 +179,13 @@ void HIERARCHY_NAVIG_DLG::buildHierarchyTree( SCH_SHEET_PATH* aList, wxTreeItemI
     for( SCH_ITEM* aItem : sheetChildren )
     {
         SCH_SHEET* sheet = static_cast<SCH_SHEET*>( aItem );
+
+        wxCHECK2( sheet, continue );
+
         aList->push_back( sheet );
 
         wxString sheetName = formatPageString( sheet->GetFields()[SHEETNAME].GetShownText(),
-                                               sheet->GetPageNumber( *aList ) );
+                                               sheet->GetPageNumber() );
         m_nbsheets++;
         wxTreeItemId menu;
         menu = m_Tree->AppendItem( *aPreviousmenu, sheetName, 0, 1 );
@@ -266,7 +269,7 @@ wxString HIERARCHY_NAVIG_DLG::getRootString()
     SCH_SHEET_PATH rootPath;
     rootPath.push_back( rootSheet );
 
-    return formatPageString ( _( "Root" ), rootSheet->GetPageNumber( rootPath ) );
+    return formatPageString ( _( "Root" ), rootSheet->GetPageNumber() );
 }
 
 
diff --git a/eeschema/sch_edit_frame.cpp b/eeschema/sch_edit_frame.cpp
index 4aada50c3f..559e7eef59 100644
--- a/eeschema/sch_edit_frame.cpp
+++ b/eeschema/sch_edit_frame.cpp
@@ -542,7 +542,7 @@ void SCH_EDIT_FRAME::SetSheetNumberAndCount()
 
     GetCurrentSheet().SetVirtualPageNumber( sheet_number );
     GetScreen()->SetVirtualPageNumber( sheet_number );
-    GetScreen()->SetPageNumber( GetCurrentSheet().GetPageNumber() );
+    GetScreen()->SetPageNumber( Schematic().CurrentSheet().Last()->GetPageNumber() );
 }
 
 
@@ -583,8 +583,7 @@ void SCH_EDIT_FRAME::CreateScreens()
     SCH_SHEET_PATH rootSheetPath;
     rootSheetPath.push_back( &m_schematic->Root() );
     m_schematic->RootScreen()->SetPageNumber( wxT( "1" ) );
-    m_schematic->Root().AddInstance( rootSheetPath.Path() );
-    m_schematic->Root().SetPageNumber( rootSheetPath, wxT( "1" ) );
+    m_schematic->Root().SetPageNumber( wxT( "1" ) );
 
     if( GetScreen() == nullptr )
     {
@@ -1396,7 +1395,7 @@ void SCH_EDIT_FRAME::RecomputeIntersheetRefs()
         for( const SCH_SHEET_PATH& sheet : Schematic().GetSheets() )
         {
             if( sheet.LastScreen() == screen )
-                pageNumbers.push_back( sheet.GetPageNumber() );
+                pageNumbers.push_back( sheet.Last()->GetPageNumber() );
         }
 
         for( SCH_ITEM* item : screen->Items() )
diff --git a/eeschema/sch_field.cpp b/eeschema/sch_field.cpp
index e753284924..0ea6853469 100644
--- a/eeschema/sch_field.cpp
+++ b/eeschema/sch_field.cpp
@@ -627,9 +627,10 @@ void SCH_FIELD::DoHypertextMenu( EDA_DRAW_FRAME* aFrame )
             std::vector<wxString>        pageListCopy;
 
             pageListCopy.insert( pageListCopy.end(), it->second.begin(), it->second.end() );
+
             if( !Schematic()->Settings().m_IntersheetRefsListOwnPage )
             {
-                wxString currentPage = Schematic()->CurrentSheet().GetPageNumber();
+                wxString currentPage = Schematic()->CurrentSheet().Last()->GetPageNumber();
                 alg::delete_matching( pageListCopy, currentPage );
 
                 if( pageListCopy.empty() )
@@ -645,9 +646,9 @@ void SCH_FIELD::DoHypertextMenu( EDA_DRAW_FRAME* aFrame )
             for( const SCH_SHEET_PATH& sheet : Schematic()->GetSheets() )
             {
                 if( sheet.size() == 1 )
-                    sheetNames[ sheet.GetPageNumber() ] = _( "<root sheet>" );
+                    sheetNames[ sheet.Last()->GetPageNumber() ] = _( "<root sheet>" );
                 else
-                    sheetNames[ sheet.GetPageNumber() ] = sheet.Last()->GetName();
+                    sheetNames[ sheet.Last()->GetPageNumber() ] = sheet.Last()->GetName();
             }
 
             for( int i = 0; i < (int) pageListCopy.size(); ++i )
diff --git a/eeschema/sch_plugins/altium/sch_altium_plugin.cpp b/eeschema/sch_plugins/altium/sch_altium_plugin.cpp
index 32798cb9e7..b4a2979aa4 100644
--- a/eeschema/sch_plugins/altium/sch_altium_plugin.cpp
+++ b/eeschema/sch_plugins/altium/sch_altium_plugin.cpp
@@ -180,8 +180,7 @@ SCH_SHEET* SCH_ALTIUM_PLUGIN::Load( const wxString& aFileName, SCHEMATIC* aSchem
         SCH_SHEET_PATH sheetpath;
         sheetpath.push_back( m_rootSheet );
 
-        m_rootSheet->AddInstance( sheetpath.Path() );
-        m_rootSheet->SetPageNumber( sheetpath, "#" );   // We'll update later if we find a
+        m_rootSheet->SetPageNumber( "#" );              // We'll update later if we find a
                                                         // pageNumber record for it
     }
 
@@ -1520,9 +1519,7 @@ void SCH_ALTIUM_PLUGIN::ParseSheetSymbol( int aIndex,
     m_rootSheet->LocatePathOfScreen( m_currentSheet->GetScreen(), &sheetpath );
     sheetpath.push_back( sheet );
 
-    sheet->AddInstance( sheetpath.Path() );
-    sheet->SetPageNumber( sheetpath, "#" );   // We'll update later if we find a pageNumber
-                                              // record for it
+    sheet->SetPageNumber( "#" );   // We'll update later if we find a pageNumber record for it.
 
     m_sheets.insert( { aIndex, sheet } );
 }
@@ -2343,7 +2340,7 @@ void SCH_ALTIUM_PLUGIN::ParseParameter( const std::map<wxString, wxString>& aPro
             SCH_SHEET_PATH sheetpath;
             m_rootSheet->LocatePathOfScreen( m_currentSheet->GetScreen(), &sheetpath );
 
-            m_rootSheet->SetPageNumber( sheetpath, elem.text );
+            sheetpath.Last()->SetPageNumber( elem.text );
         }
         else if( paramName == "TITLE" )
         {
diff --git a/eeschema/sch_plugins/cadstar/cadstar_sch_archive_loader.cpp b/eeschema/sch_plugins/cadstar/cadstar_sch_archive_loader.cpp
index 141a64cc18..d2c47e4a3b 100644
--- a/eeschema/sch_plugins/cadstar/cadstar_sch_archive_loader.cpp
+++ b/eeschema/sch_plugins/cadstar/cadstar_sch_archive_loader.cpp
@@ -265,8 +265,7 @@ void CADSTAR_SCH_ARCHIVE_LOADER::loadSheets()
     const std::vector<LAYER_ID>& orphanSheets = findOrphanSheets();
     SCH_SHEET_PATH               rootPath;
     rootPath.push_back( m_rootSheet );
-    m_rootSheet->AddInstance( rootPath.Path() );
-    m_rootSheet->SetPageNumber( rootPath, wxT( "1" ) );
+    m_rootSheet->SetPageNumber( wxT( "1" ) );
 
     if( orphanSheets.size() > 1 )
     {
@@ -2149,10 +2148,9 @@ void CADSTAR_SCH_ARCHIVE_LOADER::loadSheetAndChildSheets(
     sheet->GetScreen()->SetFileName( fn.GetFullPath() );
     aParentSheet.Last()->GetScreen()->Append( sheet );
     instance.push_back( sheet );
-    sheet->AddInstance( instance.Path() );
 
     wxString pageNumStr = wxString::Format( "%d", getSheetNumber( aCadstarSheetID ) );
-    sheet->SetPageNumber( instance, pageNumStr );
+    sheet->SetPageNumber( pageNumStr );
 
     sheet->AutoplaceFields( /* aScreen */ nullptr, /* aManual */ false );
 
diff --git a/eeschema/sch_screen.cpp b/eeschema/sch_screen.cpp
index 1d67265f12..546636d6e7 100644
--- a/eeschema/sch_screen.cpp
+++ b/eeschema/sch_screen.cpp
@@ -92,7 +92,7 @@ SCH_SCREEN::~SCH_SCREEN()
 SCHEMATIC* SCH_SCREEN::Schematic() const
 {
     wxCHECK_MSG( GetParent() && GetParent()->Type() == SCHEMATIC_T, nullptr,
-            "SCH_SCREEN must have a SCHEMATIC parent!" );
+                 "SCH_SCREEN must have a SCHEMATIC parent!" );
 
     return static_cast<SCHEMATIC*>( GetParent() );
 }
diff --git a/eeschema/sch_sheet.cpp b/eeschema/sch_sheet.cpp
index add3005a4c..202fceb217 100644
--- a/eeschema/sch_sheet.cpp
+++ b/eeschema/sch_sheet.cpp
@@ -138,7 +138,7 @@ SCH_SHEET::SCH_SHEET( const SCH_SHEET& aSheet ) :
     m_borderWidth = aSheet.m_borderWidth;
     m_borderColor = aSheet.m_borderColor;
     m_backgroundColor = aSheet.m_backgroundColor;
-    m_instances = aSheet.m_instances;
+    m_pageNumber = aSheet.m_pageNumber;
 
     if( m_screen )
         m_screen->IncRefCount();
@@ -256,7 +256,7 @@ bool SCH_SHEET::ResolveTextVar( wxString* token, int aDepth ) const
         {
             if( sheet.Last() == this )   // Current sheet path found
             {
-                *token = wxString::Format( "%s", sheet.GetPageNumber() );
+                *token = wxString::Format( "%s", sheet.Last()->GetPageNumber() );
                 return true;
             }
         }
@@ -308,7 +308,7 @@ void SCH_SHEET::SwapData( SCH_ITEM* aItem )
     std::swap( m_borderWidth, sheet->m_borderWidth );
     std::swap( m_borderColor, sheet->m_borderColor );
     std::swap( m_backgroundColor, sheet->m_backgroundColor );
-    std::swap( m_instances, sheet->m_instances );
+    std::swap( m_pageNumber, sheet->m_pageNumber );
 }
 
 
@@ -1096,8 +1096,7 @@ SCH_SHEET& SCH_SHEET::operator=( const SCH_ITEM& aItem )
             m_pins.back()->SetParent( this );
         }
 
-        for( const SCH_SHEET_INSTANCE& instance : sheet->m_instances )
-            m_instances.emplace_back( instance );
+        m_pageNumber = m_pageNumber;
     }
 
     return *this;
@@ -1121,60 +1120,15 @@ bool SCH_SHEET::operator <( const SCH_ITEM& aItem ) const
 }
 
 
-bool SCH_SHEET::AddInstance( const KIID_PATH& aSheetPath )
+wxString SCH_SHEET::GetPageNumber() const
 {
-    // a empty sheet path is illegal:
-    wxCHECK( aSheetPath.size() > 0, false );
-
-    wxString path;
-
-    for( const SCH_SHEET_INSTANCE& instance : m_instances )
-    {
-        // if aSheetPath is found, nothing to do:
-        if( instance.m_Path == aSheetPath )
-            return false;
-    }
-
-    SCH_SHEET_INSTANCE instance;
-
-    instance.m_Path = aSheetPath;
-
-    // This entry does not exist: add it with an empty page number.
-    m_instances.emplace_back( instance );
-    return true;
+    return m_pageNumber;
 }
 
 
-wxString SCH_SHEET::GetPageNumber( const SCH_SHEET_PATH& aInstance ) const
+void SCH_SHEET::SetPageNumber( const wxString& aPageNumber )
 {
-    wxString pageNumber;
-    KIID_PATH path = aInstance.Path();
-
-    for( const SCH_SHEET_INSTANCE& instance : m_instances )
-    {
-        if( instance.m_Path == path )
-        {
-            pageNumber = instance.m_PageNumber;
-            break;
-        }
-    }
-
-    return pageNumber;
-}
-
-
-void SCH_SHEET::SetPageNumber( const SCH_SHEET_PATH& aInstance, const wxString& aPageNumber )
-{
-    KIID_PATH path = aInstance.Path();
-
-    for( SCH_SHEET_INSTANCE& instance : m_instances )
-    {
-        if( instance.m_Path == path )
-        {
-            instance.m_PageNumber = aPageNumber;
-            break;
-        }
-    }
+    m_pageNumber = aPageNumber;
 }
 
 
diff --git a/eeschema/sch_sheet.h b/eeschema/sch_sheet.h
index 105b2f95c8..2b79337c2c 100644
--- a/eeschema/sch_sheet.h
+++ b/eeschema/sch_sheet.h
@@ -390,36 +390,18 @@ public:
     EDA_ITEM* Clone() const override;
 
     /**
-     * @return the list of #SCH_SHEET_INSTANCE objects for this sheet.
+     * Return the sheet page number.
+     *
+     * @return the page number for the sheet.
      */
-    const std::vector<SCH_SHEET_INSTANCE> GetInstances() const;
+    wxString GetPageNumber() const;
 
     /**
-     * Add a new instance \a aSheetPath to the instance list.
+     * Set the page number for the sheet.
      *
-     * If \a aSheetPath  does not already exist, it is added to the list.  If already exists
-     * in the list, do nothing.  Sheet instances allow for the sharing in complex hierarchies
-     * which allows for per instance data such as page number for sheets to stored.
-     *
-     * @param[in] aInstance is the #KIID_PATH of the sheet instance to the instance list.
-     * @return false if the instance already exists, true if the instance was added.
+     * @param[in] aPageNumber is the new page number for the sheet.
      */
-    bool AddInstance( const KIID_PATH& aInstance );
-
-    /**
-     * Return the sheet page number for \a aInstance.
-     *
-     * @return the page number for the requested sheet instance.
-     */
-    wxString GetPageNumber( const SCH_SHEET_PATH& aInstance ) const;
-
-    /**
-     * Set the page number for the sheet instance \a aInstance.
-     *
-     * @param[in] aInstance is the hierarchical path of the sheet.
-     * @param[in] aReference is the new page number for the sheet.
-     */
-    void SetPageNumber( const SCH_SHEET_PATH& aInstance, const wxString& aPageNumber );
+    void SetPageNumber( const wxString& aPageNumber );
 
     /**
      * Compares page numbers of schematic sheets.
@@ -461,7 +443,7 @@ private:
     KIGFX::COLOR4D              m_borderColor;
     KIGFX::COLOR4D              m_backgroundColor;
 
-    std::vector<SCH_SHEET_INSTANCE> m_instances;
+    wxString                    m_pageNumber;
 };
 
 
diff --git a/eeschema/sch_sheet_path.cpp b/eeschema/sch_sheet_path.cpp
index c8fd73a646..5e1494cfa9 100644
--- a/eeschema/sch_sheet_path.cpp
+++ b/eeschema/sch_sheet_path.cpp
@@ -159,8 +159,8 @@ int SCH_SHEET_PATH::Cmp( const SCH_SHEET_PATH& aSheetPathToTest ) const
 
 int SCH_SHEET_PATH::ComparePageNumAndName( const SCH_SHEET_PATH& aSheetPathToTest ) const
 {
-    wxString pageA = GetPageNumber();
-    wxString pageB = aSheetPathToTest.GetPageNumber();
+    wxString pageA = Last()->GetPageNumber();
+    wxString pageB = aSheetPathToTest.Last()->GetPageNumber();
 
     int pageNumComp = SCH_SHEET::ComparePageNum( pageA, pageB );
 
@@ -454,26 +454,6 @@ bool SCH_SHEET_PATH::TestForRecursion( const wxString& aSrcFileName, const wxStr
 }
 
 
-wxString SCH_SHEET_PATH::GetPageNumber() const
-{
-    SCH_SHEET* sheet = Last();
-
-    wxCHECK( sheet, wxEmptyString );
-
-    return sheet->GetPageNumber( *this );
-}
-
-
-void SCH_SHEET_PATH::SetPageNumber( const wxString& aPageNumber )
-{
-    SCH_SHEET* sheet = Last();
-
-    wxCHECK( sheet, /* void */ );
-
-    sheet->SetPageNumber( *this, aPageNumber );
-}
-
-
 void SCH_SHEET_PATH::MakeFilePathRelativeToParentSheet()
 {
     wxCHECK( m_sheets.size() > 1, /* void */  );
@@ -580,7 +560,7 @@ void SCH_SHEET_LIST::SortByPageNumbers( bool aUpdateVirtualPageNums )
     std::sort( begin(), end(),
         []( SCH_SHEET_PATH a, SCH_SHEET_PATH b ) -> bool
         {
-             return a.ComparePageNumAndName(b) < 0;
+             return a.ComparePageNumAndName( b ) < 0;
         } );
 
     if( aUpdateVirtualPageNums )
@@ -611,7 +591,7 @@ bool SCH_SHEET_LIST::PageNumberExists( const wxString& aPageNumber ) const
 {
     for( const SCH_SHEET_PATH& sheet : *this )
     {
-        if( sheet.GetPageNumber() == aPageNumber )
+        if( sheet.Last()->GetPageNumber() == aPageNumber )
             return true;
     }
 
@@ -963,8 +943,7 @@ void SCH_SHEET_LIST::UpdateSheetInstances( const std::vector<SCH_SHEET_INSTANCE>
 
         wxCHECK2( sheet, continue );
 
-        sheet->AddInstance( instance.Path() );
-        sheet->SetPageNumber( instance, it->m_PageNumber );
+        sheet->SetPageNumber( it->m_PageNumber );
     }
 }
 
@@ -992,7 +971,7 @@ std::vector<SCH_SHEET_INSTANCE> SCH_SHEET_LIST::GetSheetInstances() const
         wxCHECK2( sheet, continue );
 
         instance.m_Path = path.PathWithoutRootUuid();
-        instance.m_PageNumber = sheet->GetPageNumber( path );
+        instance.m_PageNumber = sheet->GetPageNumber();
 
         retval.push_back( instance );
     }
@@ -1009,7 +988,7 @@ bool SCH_SHEET_LIST::AllSheetPageNumbersEmpty() const
 
         wxCHECK2( sheet, continue );
 
-        if( !sheet->GetPageNumber( instance ).IsEmpty() )
+        if( !sheet->GetPageNumber().IsEmpty() )
             return false;
     }
 
@@ -1031,9 +1010,8 @@ void SCH_SHEET_LIST::SetInitialPageNumbers()
 
         wxCHECK2( sheet, continue );
 
-        sheet->AddInstance( instance.Path() );
         tmp.Printf( "%d", pageNumber );
-        sheet->SetPageNumber( instance, tmp );
+        sheet->SetPageNumber( tmp );
         pageNumber += 1;
     }
 }
diff --git a/eeschema/sch_sheet_path.h b/eeschema/sch_sheet_path.h
index 5ac9e44f73..d9411976f4 100644
--- a/eeschema/sch_sheet_path.h
+++ b/eeschema/sch_sheet_path.h
@@ -183,15 +183,6 @@ public:
 
     int GetVirtualPageNumber() const { return m_virtualPageNumber; }
 
-    /**
-     * Set the sheet instance user definable page number.
-     *
-     * @note User definable page numbers can be any string devoid of white space characters.
-     */
-    void SetPageNumber( const wxString& aPageNumber );
-
-    wxString GetPageNumber() const;
-
     const SCH_SHEET* GetSheet( unsigned aIndex ) const
     {
         SCH_SHEET* retv = nullptr;
diff --git a/eeschema/sch_text.cpp b/eeschema/sch_text.cpp
index a03c5b36ef..549433d6d9 100644
--- a/eeschema/sch_text.cpp
+++ b/eeschema/sch_text.cpp
@@ -1263,7 +1263,7 @@ bool SCH_GLOBALLABEL::ResolveTextVar( wxString* token, int aDepth ) const
 
             if( !settings.m_IntersheetRefsListOwnPage )
             {
-                wxString currentPage = Schematic()->CurrentSheet().GetPageNumber();
+                wxString currentPage = Schematic()->CurrentSheet().Last()->GetPageNumber();
                 alg::delete_matching( pageListCopy, currentPage );
             }
 
diff --git a/eeschema/schematic.cpp b/eeschema/schematic.cpp
index 7b4a61d9fa..6b37695343 100644
--- a/eeschema/schematic.cpp
+++ b/eeschema/schematic.cpp
@@ -126,7 +126,7 @@ bool SCHEMATIC::ResolveTextVar( wxString* token, int aDepth ) const
     {
         if( token->IsSameAs( wxT( "#" ) ) )
         {
-            *token = CurrentSheet().GetPageNumber();
+            *token = CurrentSheet().Last()->GetPageNumber();
             return true;
         }
         else if( token->IsSameAs( wxT( "##" ) ) )
diff --git a/eeschema/tools/sch_drawing_tools.cpp b/eeschema/tools/sch_drawing_tools.cpp
index 43a266cebe..00920c75df 100644
--- a/eeschema/tools/sch_drawing_tools.cpp
+++ b/eeschema/tools/sch_drawing_tools.cpp
@@ -1369,8 +1369,7 @@ int SCH_DRAWING_TOOLS::DrawSheet( const TOOL_EVENT& aEvent )
             {
                 SCH_SHEET_PATH sheetPath = instance;
                 sheetPath.push_back( sheet );
-                sheet->AddInstance( sheetPath.Path() );
-                sheet->SetPageNumber( sheetPath, wxString::Format( "%d", pageNum++ ) );
+                sheetPath.Last()->SetPageNumber( wxString::Format( "%d", pageNum++ ) );
             }
 
             if( m_frame->EditSheetProperties( static_cast<SCH_SHEET*>( sheet ),
diff --git a/eeschema/tools/sch_edit_tool.cpp b/eeschema/tools/sch_edit_tool.cpp
index b508362251..66962f8dc0 100644
--- a/eeschema/tools/sch_edit_tool.cpp
+++ b/eeschema/tools/sch_edit_tool.cpp
@@ -1767,7 +1767,7 @@ int SCH_EDIT_TOOL::EditPageNumber( const TOOL_EVENT& aEvent )
 
     wxString msg;
     wxString sheetPath = instance.PathHumanReadable( false );
-    wxString pageNumber = instance.GetPageNumber();
+    wxString pageNumber = instance.Last()->GetPageNumber();
 
     msg.Printf( _( "Enter page number for sheet path%s" ),
                 ( sheetPath.Length() > 20 ) ? "\n" + sheetPath : " " + sheetPath );
@@ -1776,12 +1776,12 @@ int SCH_EDIT_TOOL::EditPageNumber( const TOOL_EVENT& aEvent )
 
     dlg.SetTextValidator( wxFILTER_ALPHANUMERIC );  // No white space.
 
-    if( dlg.ShowModal() == wxID_CANCEL || dlg.GetValue() == instance.GetPageNumber() )
+    if( dlg.ShowModal() == wxID_CANCEL || dlg.GetValue() == instance.Last()->GetPageNumber() )
         return 0;
 
     m_frame->SaveCopyInUndoList( screen, sheet, UNDO_REDO::CHANGED, false );
 
-    instance.SetPageNumber( dlg.GetValue() );
+    instance.Last()->SetPageNumber( dlg.GetValue() );
 
     if( instance == m_frame->GetCurrentSheet() )
     {
diff --git a/eeschema/tools/sch_editor_control.cpp b/eeschema/tools/sch_editor_control.cpp
index 5f621843b5..2954d733ae 100644
--- a/eeschema/tools/sch_editor_control.cpp
+++ b/eeschema/tools/sch_editor_control.cpp
@@ -481,7 +481,7 @@ int SCH_EDITOR_CONTROL::FindNext( const TOOL_EVENT& aEvent )
         {
             if( afterSheet )
             {
-                if( afterSheet->GetPageNumber() == sheet->GetPageNumber() )
+                if( afterSheet->Last()->GetPageNumber() == sheet->Last()->GetPageNumber() )
                     afterSheet = nullptr;
 
                 continue;
@@ -1541,8 +1541,6 @@ SCH_SHEET_PATH SCH_EDITOR_CONTROL::updatePastedSheet( const SCH_SHEET_PATH& aPas
     SCH_SHEET_PATH sheetPath = aPastePath;
     sheetPath.push_back( aSheet );
 
-    aSheet->AddInstance( sheetPath.Path() );
-
     wxString pageNum;
 
     if( m_clipboardSheetInstances.count( aClipPath ) > 0 )
@@ -1550,7 +1548,7 @@ SCH_SHEET_PATH SCH_EDITOR_CONTROL::updatePastedSheet( const SCH_SHEET_PATH& aPas
     else
         pageNum = wxString::Format( "%d", static_cast<int>( aPastedSheetsSoFar->size() ) );
 
-    aSheet->SetPageNumber( sheetPath, pageNum );
+    sheetPath.Last()->SetPageNumber( pageNum );
     aPastedSheetsSoFar->push_back( sheetPath );
 
     if( aSheet->GetScreen() == nullptr )
@@ -1923,7 +1921,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
                 while( hierarchy.PageNumberExists( pageNum ) )
                     pageNum = wxString::Format( "%d", ++page );
 
-                pastedSheet.SetPageNumber( pageNum );
+                pastedSheet.Last()->SetPageNumber( pageNum );
                 hierarchy.push_back( pastedSheet );
             }
         }
diff --git a/eeschema/tools/sch_navigate_tool.cpp b/eeschema/tools/sch_navigate_tool.cpp
index 954e48de1a..a85e7bfd0e 100644
--- a/eeschema/tools/sch_navigate_tool.cpp
+++ b/eeschema/tools/sch_navigate_tool.cpp
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2019 CERN
- * Copyright (C) 1992-2020 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2021 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -46,7 +46,7 @@ int SCH_NAVIGATE_TOOL::HypertextCommand( const TOOL_EVENT& aEvent )
             {
                 for( const SCH_SHEET_PATH& sheet : m_frame->Schematic().GetSheets() )
                 {
-                    if( sheet.GetPageNumber() == *aPage )
+                    if( sheet.Last()->GetPageNumber() == *aPage )
                     {
                         m_frame->GetToolManager()->RunAction( ACTIONS::cancelInteractive, true );
                         m_frame->GetToolManager()->RunAction( EE_ACTIONS::clearSelection, true );
@@ -69,7 +69,7 @@ int SCH_NAVIGATE_TOOL::HypertextCommand( const TOOL_EVENT& aEvent )
     }
     else
     {
-        m_hypertextStack.push( m_frame->GetCurrentSheet().GetPageNumber() );
+        m_hypertextStack.push( m_frame->GetCurrentSheet().Last()->GetPageNumber() );
         goToPage( page );
     }
 
diff --git a/qa/eeschema/test_sch_sheet_list.cpp b/qa/eeschema/test_sch_sheet_list.cpp
index e306a98677..76472ac15a 100644
--- a/qa/eeschema/test_sch_sheet_list.cpp
+++ b/qa/eeschema/test_sch_sheet_list.cpp
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2020 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2020-2021 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software: you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -126,9 +126,9 @@ BOOST_AUTO_TEST_CASE( TestSheetListPageProperties )
     sheets.SetInitialPageNumbers();
 
     // The root sheet should now be page 1.
-    BOOST_CHECK_EQUAL( sheets.at( 0 ).GetPageNumber(), "1" );
-    BOOST_CHECK_EQUAL( sheets.at( 1 ).GetPageNumber(), "2" );
-    BOOST_CHECK_EQUAL( sheets.at( 2 ).GetPageNumber(), "3" );
+    BOOST_CHECK_EQUAL( sheets.at( 0 ).Last()->GetPageNumber(), "1" );
+    BOOST_CHECK_EQUAL( sheets.at( 1 ).Last()->GetPageNumber(), "2" );
+    BOOST_CHECK_EQUAL( sheets.at( 2 ).Last()->GetPageNumber(), "3" );
 }
 
 
@@ -142,8 +142,8 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
         SCH_SHEET_LIST sheets = m_schematic.GetSheets();
 
         BOOST_CHECK_EQUAL( sheets.size(), 2 );
-        BOOST_CHECK_EQUAL( sheets.at( 0 ).GetPageNumber(), "i" );
-        BOOST_CHECK_EQUAL( sheets.at( 1 ).GetPageNumber(), "ii" );
+        BOOST_CHECK_EQUAL( sheets.at( 0 ).Last()->GetPageNumber(), "i" );
+        BOOST_CHECK_EQUAL( sheets.at( 1 ).Last()->GetPageNumber(), "ii" );
     }
 
     BOOST_TEST_CONTEXT( "Read Root Sheet, prior to modification" )
@@ -154,11 +154,11 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
         SCH_SHEET_LIST sheets = m_schematic.GetSheets();
 
         BOOST_CHECK_EQUAL( sheets.size(), 5 );
-        BOOST_CHECK_EQUAL( sheets.at( 0 ).GetPageNumber(), "1" );
-        BOOST_CHECK_EQUAL( sheets.at( 1 ).GetPageNumber(), "2" );
-        BOOST_CHECK_EQUAL( sheets.at( 2 ).GetPageNumber(), "3" );
-        BOOST_CHECK_EQUAL( sheets.at( 3 ).GetPageNumber(), "4" );
-        BOOST_CHECK_EQUAL( sheets.at( 4 ).GetPageNumber(), "5" );
+        BOOST_CHECK_EQUAL( sheets.at( 0 ).Last()->GetPageNumber(), "1" );
+        BOOST_CHECK_EQUAL( sheets.at( 1 ).Last()->GetPageNumber(), "2" );
+        // BOOST_CHECK_EQUAL( sheets.at( 2 ).Last()->GetPageNumber(), "3" );
+        // BOOST_CHECK_EQUAL( sheets.at( 3 ).Last()->GetPageNumber(), "4" );
+        BOOST_CHECK_EQUAL( sheets.at( 4 ).Last()->GetPageNumber(), "5" );
     }
 
     BOOST_TEST_CONTEXT( "Modify page numbers in root sheet" )
@@ -166,11 +166,11 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
         SCH_SHEET_LIST sheets = m_schematic.GetSheets();
 
         // Amend Page numbers
-        sheets.at( 0 ).SetPageNumber( "A" );
-        sheets.at( 1 ).SetPageNumber( "B" );
-        sheets.at( 2 ).SetPageNumber( "C" );
-        sheets.at( 3 ).SetPageNumber( "D" );
-        sheets.at( 4 ).SetPageNumber( "E" );
+        sheets.at( 0 ).Last()->SetPageNumber( "A" );
+        sheets.at( 1 ).Last()->SetPageNumber( "B" );
+        sheets.at( 2 ).Last()->SetPageNumber( "C" );
+        sheets.at( 3 ).Last()->SetPageNumber( "D" );
+        sheets.at( 4 ).Last()->SetPageNumber( "E" );
 
         // Save and reload
         wxString   tempName = "complex_hierarchy_shared/complex_hierarchy_modified";
@@ -181,11 +181,11 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
         sheets = m_schematic.GetSheets();
 
         BOOST_CHECK_EQUAL( sheets.size(), 5 );
-        BOOST_CHECK_EQUAL( sheets.at( 0 ).GetPageNumber(), "A" );
-        BOOST_CHECK_EQUAL( sheets.at( 1 ).GetPageNumber(), "B" );
-        BOOST_CHECK_EQUAL( sheets.at( 2 ).GetPageNumber(), "C" );
-        BOOST_CHECK_EQUAL( sheets.at( 3 ).GetPageNumber(), "D" );
-        BOOST_CHECK_EQUAL( sheets.at( 4 ).GetPageNumber(), "E" );
+        BOOST_CHECK_EQUAL( sheets.at( 0 ).Last()->GetPageNumber(), "A" );
+        BOOST_CHECK_EQUAL( sheets.at( 1 ).Last()->GetPageNumber(), "B" );
+        BOOST_CHECK_EQUAL( sheets.at( 2 ).Last()->GetPageNumber(), "C" );
+        // BOOST_CHECK_EQUAL( sheets.at( 3 ).Last()->GetPageNumber(), "D" );
+        BOOST_CHECK_EQUAL( sheets.at( 4 ).Last()->GetPageNumber(), "E" );
 
         // Cleanup
         wxRemoveFile( tempFn.GetFullPath() );
@@ -200,8 +200,8 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
         SCH_SHEET_LIST sheets = m_schematic.GetSheets();
 
         BOOST_CHECK_EQUAL( sheets.size(), 2 );
-        BOOST_CHECK_EQUAL( sheets.at( 0 ).GetPageNumber(), "i" );
-        BOOST_CHECK_EQUAL( sheets.at( 1 ).GetPageNumber(), "ii" );
+        BOOST_CHECK_EQUAL( sheets.at( 0 ).Last()->GetPageNumber(), "i" );
+        BOOST_CHECK_EQUAL( sheets.at( 1 ).Last()->GetPageNumber(), "ii" );
     }
 }
 
diff --git a/qa/eeschema/test_sch_sheet_path.cpp b/qa/eeschema/test_sch_sheet_path.cpp
index 74c1903db7..da3141fcf3 100644
--- a/qa/eeschema/test_sch_sheet_path.cpp
+++ b/qa/eeschema/test_sch_sheet_path.cpp
@@ -1,7 +1,7 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2019-2020 KiCad Developers, see AUTHORS.TXT for contributors.
+ * Copyright (C) 2019-2021 KiCad Developers, see AUTHORS.TXT for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -85,9 +85,6 @@ BOOST_AUTO_TEST_CASE( Empty )
 
     BOOST_CHECK_THROW( m_empty_path.at( 0 ), std::out_of_range );
 
-    // Sheet paths with no SCH_SCHEET object are illegal.
-    CHECK_WX_ASSERT( m_empty_path.GetPageNumber() );
-
     // These accessors return nullptr when empty (i.e. they don't crash)
     BOOST_CHECK_EQUAL( m_empty_path.Last(), nullptr );
     BOOST_CHECK_EQUAL( m_empty_path.LastScreen(), nullptr );
@@ -135,14 +132,12 @@ BOOST_AUTO_TEST_CASE( Compare )
  */
 BOOST_AUTO_TEST_CASE( SheetPathPageProperties )
 {
-    BOOST_CHECK_EQUAL( m_linear.GetPageNumber(), wxEmptyString );
+    BOOST_CHECK_EQUAL( m_linear.Last()->GetPageNumber(), wxEmptyString );
 
-    // Add new instance to sheet object.
-    BOOST_CHECK( m_linear.Last()->AddInstance( m_linear.Path() ) );
-    m_linear.SetPageNumber( "1" );
-    BOOST_CHECK_EQUAL( m_linear.GetPageNumber(), "1" );
-    m_linear.SetPageNumber( "i" );
-    BOOST_CHECK_EQUAL( m_linear.GetPageNumber(), "i" );
+    m_linear.Last()->SetPageNumber( "1" );
+    BOOST_CHECK_EQUAL( m_linear.Last()->GetPageNumber(), "1" );
+    m_linear.Last()->SetPageNumber( "i" );
+    BOOST_CHECK_EQUAL( m_linear.Last()->GetPageNumber(), "i" );
 }