diff --git a/src/settings_gui.cpp b/src/settings_gui.cpp
--- a/src/settings_gui.cpp
+++ b/src/settings_gui.cpp
@@ -2989,6 +2989,7 @@ struct CustomCurrencyWindow : Window {
 	{
 		switch (widget) {
 			case WID_CC_RATE:      SetDParam(0, 1); SetDParam(1, 1);            break;
+			case WID_CC_SEPARATOR: SetDParamStr(0, _custom_currency.separator); break;
 			case WID_CC_PREFIX:    SetDParamStr(0, _custom_currency.prefix);    break;
 			case WID_CC_SUFFIX:    SetDParamStr(0, _custom_currency.suffix);    break;
 			case WID_CC_YEAR:
@@ -3014,6 +3015,7 @@ struct CustomCurrencyWindow : Window {
 				break;
 
 			/* Set the appropriate width for the edit buttons. */
+			case WID_CC_SEPARATOR_EDIT:
 			case WID_CC_PREFIX_EDIT:
 			case WID_CC_SUFFIX_EDIT:
 				*size = maxdim(*size, {(uint)SETTING_BUTTON_WIDTH, (uint)SETTING_BUTTON_HEIGHT});
@@ -3056,6 +3058,14 @@ struct CustomCurrencyWindow : Window {
 				afilter = CS_NUMERAL;
 				break;
 
+			case WID_CC_SEPARATOR_EDIT:
+			case WID_CC_SEPARATOR:
+				SetDParamStr(0, _custom_currency.separator);
+				str = STR_JUST_RAW_STRING;
+				len = 7;
+				line = WID_CC_SEPARATOR;
+				break;
+
 			case WID_CC_PREFIX_EDIT:
 			case WID_CC_PREFIX:
 				SetDParamStr(0, _custom_currency.prefix);
@@ -3111,6 +3121,10 @@ struct CustomCurrencyWindow : Window {
 				_custom_currency.rate = Clamp(atoi(str), 1, UINT16_MAX);
 				break;
 
+			case WID_CC_SEPARATOR: // Thousands separator
+				_custom_currency.separator = str;
+				break;
+
 			case WID_CC_PREFIX:
 				_custom_currency.prefix = str;
 				break;
@@ -3152,6 +3166,10 @@ static constexpr NWidgetPart _nested_cus
 					NWidget(WWT_TEXT, COLOUR_BLUE, WID_CC_RATE), SetDataTip(STR_CURRENCY_EXCHANGE_RATE, STR_CURRENCY_SET_EXCHANGE_RATE_TOOLTIP), SetFill(1, 0),
 				EndContainer(),
 				NWidget(NWID_HORIZONTAL), SetPIP(0, WidgetDimensions::unscaled.hsep_wide, 0),
+					NWidget(WWT_PUSHBTN, COLOUR_DARK_BLUE, WID_CC_SEPARATOR_EDIT), SetDataTip(0x0, STR_CURRENCY_SET_CUSTOM_CURRENCY_SEPARATOR_TOOLTIP), SetFill(0, 1),
+					NWidget(WWT_TEXT, COLOUR_BLUE, WID_CC_SEPARATOR), SetDataTip(STR_CURRENCY_SEPARATOR, STR_CURRENCY_SET_CUSTOM_CURRENCY_SEPARATOR_TOOLTIP), SetFill(1, 0),
+				EndContainer(),
+				NWidget(NWID_HORIZONTAL), SetPIP(0, WidgetDimensions::unscaled.hsep_wide, 0),
 					NWidget(WWT_PUSHBTN, COLOUR_DARK_BLUE, WID_CC_PREFIX_EDIT), SetDataTip(0x0, STR_CURRENCY_SET_CUSTOM_CURRENCY_PREFIX_TOOLTIP), SetFill(0, 1),
 					NWidget(WWT_TEXT, COLOUR_BLUE, WID_CC_PREFIX), SetDataTip(STR_CURRENCY_PREFIX, STR_CURRENCY_SET_CUSTOM_CURRENCY_PREFIX_TOOLTIP), SetFill(1, 0),
 				EndContainer(),