diff --git a/src/table/settings/gui_settings.ini b/src/table/settings/gui_settings.ini
--- a/src/table/settings/gui_settings.ini
+++ b/src/table/settings/gui_settings.ini
@@ -16,6 +16,7 @@ static void InvalidateCompanyLiveryWindo
 static void InvalidateNewGRFChangeWindows(int32_t new_value);
 static void ZoomMinMaxChanged(int32_t new_value);
 static void SpriteZoomMinChanged(int32_t new_value);
+void InitializeNumberFormats();
 
 static constexpr std::initializer_list<const char*> _osk_activation{"disabled", "double", "single", "immediately"};
 static constexpr std::initializer_list<const char*> _savegame_date{"long", "short", "iso"};
@@ -905,6 +906,24 @@ cat      = SC_BASIC
 startup  = true
 
 [SDTC_SSTR]
+var      = gui.number_format
+flags    = SF_NOT_IN_SAVE | SF_NO_NETWORK_SYNC
+type     = SLE_STRQ
+def      = nullptr
+pre_cb   = [](auto format) { NumberFormatSeparators separators; return !ParseNumberFormatSeparators(separators, format).has_value(); }
+post_cb  = [](auto) { InitializeNumberFormats(); MarkWholeScreenDirty(); }
+startup  = true
+
+[SDTC_SSTR]
+var      = gui.number_abbreviations
+flags    = SF_NOT_IN_SAVE | SF_NO_NETWORK_SYNC
+type     = SLE_STRQ
+def      = nullptr
+pre_cb   = [](auto format) { NumberAbbreviations abbreviations; return !ParseNumberAbbreviations(abbreviations, format).has_value(); }
+post_cb  = [](auto) { InitializeNumberFormats(); MarkWholeScreenDirty(); }
+startup  = true
+
+[SDTC_SSTR]
 var      = gui.digit_decimal_separator
 flags    = SF_NOT_IN_SAVE | SF_NO_NETWORK_SYNC
 type     = SLE_STRQ