diff --git a/assets/js/public.js b/assets/js/public.js
index 6a07408..5a3d24f 100644
--- a/assets/js/public.js
+++ b/assets/js/public.js
@@ -234,7 +234,42 @@
                 if (woolab.ares_fill) {
                   // Compatibility with Fluid Checkout for WooCommerce – Lite
                   if ($('#billing_same_as_shipping') && $('#billing_same_as_shipping').is(':checked')) {
-                    $('#billing_same_as_shipping').click();
+                    // Check whether the CollapsibleBlock library is available
+                    if (window.CollapsibleBlock) {
+                      // Set billing address as different from shipping address
+                      var fc_billing_same_as_shipping_field = document.querySelector('#billing_same_as_shipping');
+                      fc_billing_same_as_shipping_field.checked = false; // Expand the billing address fields
+
+                      var fc_billing_address_fields_wrapper = document.querySelector('#woocommerce-billing-fields__field-wrapper');
+
+                      if (fc_billing_address_fields_wrapper) {
+                        CollapsibleBlock.expand(fc_billing_address_fields_wrapper);
+                      } // Get company field toggle and content elements
+
+
+                      var fc_billing_company_toggle = document.querySelector('#fc-expansible-form-section__toggle-plus--billing_company');
+                      var fc_billing_company_content = document.querySelector('#fc-expansible-form-section__content--billing_company'); // Expand the billing company field
+
+                      if (fc_billing_company_toggle) {
+                        CollapsibleBlock.collapse(fc_billing_company_toggle);
+                      }
+
+                      if (fc_billing_company_content) {
+                        CollapsibleBlock.expand(fc_billing_company_content);
+                      } // Get dic field toggle and content elements
+
+
+                      var fc_billing_dic_toggle = document.querySelector('#fc-expansible-form-section__toggle-plus--billing_dic');
+                      var fc_billing_dic_content = document.querySelector('#fc-expansible-form-section__content--billing_dic'); // Expand the billing dic field
+
+                      if (fc_billing_dic_toggle) {
+                        CollapsibleBlock.collapse(fc_billing_dic_toggle);
+                      }
+
+                      if (fc_billing_dic_content) {
+                        CollapsibleBlock.expand(fc_billing_dic_content);
+                      }
+                    }
                   } // Update values
 
 
diff --git a/assets/js/public.min.js b/assets/js/public.min.js
index 40c601e..9f060f3 100644
--- a/assets/js/public.min.js
+++ b/assets/js/public.min.js
@@ -1 +1 @@
-"use strict";!function(i){var l="";function e(){var e;switch(woolab.ares_fill&&(i(".woolab-ic-dic-tip").remove(),c()),i("#billing_ic_field").slideDown(),i("#billing_dic_field").slideDown(),i("#billing_country").val()){case"SK":i("#billing_dic_dph_field").slideDown(),i("#billing_dic_field > label").addClass("woolab-ic-dic-required");break;case"CZ":i("#billing_dic_dph_field").slideUp(),i("#billing_dic_field > label").removeClass("woolab-ic-dic-required");break;default:i("#billing_dic_dph_field").slideUp(),i("#billing_dic_field > label").removeClass("woolab-ic-dic-required")}woolab.ares_check&&(t(e=i("#billing_ic")),i(document.body).on("focusin","#billing_ic",function(){l=e.val()}),e.donetyping(function(){(e=i("#billing_ic")).val()!==l&&t(e)},500)),i("#billing_company_field").slideDown()}function n(){var l="SK"==i("#billing_country").val()?"billing_dic_dph":"billing_dic";i("#billing_company, #billing_ic, #billing_dic, #billing_dic_dph").each(function(e,n){n.getAttribute("data-value")&&(n.value=n.getAttribute("data-value"),n.id==l&&n.value.length&&i(document.body).trigger("update_checkout"))})}function o(i){i.removeClass("kbnt-wrong").removeClass("woocommerce-invalid")}function a(i){i.addClass("kbnt-wrong").addClass("woocommerce-invalid").removeClass("woocommerce-validated")}function c(){i("#billing_company").removeAttr("readonly"),i("#billing_dic").removeAttr("readonly"),i("#billing_postcode").removeAttr("readonly"),i("#billing_city").removeAttr("readonly"),i("#billing_address_1").removeAttr("readonly")}function t(e){if("CZ"===i("#billing_country").val()){var n=e.val();if(n!==l){var t=i("#billing_ic_field"),r='<span role="alert" class="woolab-ic-dic-tip">'+woolab.l18n_not_valid+"</span>";i(".woolab-ic-dic-tip").remove(),o(t),t.removeClass("kbnt-ok").removeClass("woocommerce-validated"),7!=n.length&&8!=n.length||null==n.match(/^[0-9]+$/)?(c(),n.length>0?a(t):o(t)):i.ajax({url:woolab.ajaxurl,data:{action:"ajaxAres",ico:n},beforeSend:function(){t.addClass("kbnt-validating"),t.append('<span role="info" class="woolab-ic-dic-tip">'+woolab.l18n_validating+"</span>")},success:function(l){(t.removeClass("kbnt-validating"),l)?0==(l=JSON.parse(l)).error?(i(".woolab-ic-dic-tip").remove(),t.addClass("kbnt-ok").addClass("woocommerce-validated").removeClass("woocommerce-invalid"),woolab.ares_fill&&(i("#billing_same_as_shipping")&&i("#billing_same_as_shipping").is(":checked")&&i("#billing_same_as_shipping").click(),i("#billing_company").val(l.spolecnost).attr("readonly",!0),i("#billing_dic").val(l.dic).attr("readonly",!0),i("#billing_address_1").val(l.adresa).attr("readonly",!0),i("#billing_postcode").val(l.psc).attr("readonly",!0),i("#billing_city").val(l.mesto).attr("readonly",!0),t.append('<span role="info" class="woolab-ic-dic-tip">'+woolab.l18n_ok+"</span>"),i("body").trigger("update_checkout"))):(d(t),i(".woolab-ic-dic-tip").length>0&&i(".woolab-ic-dic-tip").remove(),c(),t.append('<span role="alert" class="woolab-ic-dic-tip error">'+l.error+"</span>")):(d(t),0==i(".woolab-ic-dic-tip").length&&(c(),t.append(r)))},error:function(l){0==i(".woolab-ic-dic-tip").length&&(e.val(""),d(t),t.append('<span role="alert" class="woolab-ic-dic-tip error">'+woolab.l18n_error+"</span>"))}}),l=e.val()}}}function d(l){woolab.ares_fill&&(i("#billing_company").val(""),i("#billing_dic").val(""),i("#billing_postcode").val(""),i("#billing_city").val(""),i("#billing_address_1").val(""),c()),a(l)}i.fn.extend({donetyping:function(l,e){e=e||1e3;var n,o=function(i){n&&(n=null,l.call(i))};return this.each(function(l,a){var c=i(a);c.is(":input")&&i(document.body).on("keyup keypress paste",a,function(i){"keyup"==i.type&&8!=i.keyCode||(n&&clearTimeout(n),n=setTimeout(function(){o(a)},e))}),c.is(":input")&&i(document.body).on("blur",a,function(){o(a)})})}}),i(document).ready(function(){i(document.body).on("input",".woolab-ic-dic-no_spaces input",function(){i(this).val(function(i,l){return l.replace(/\s+/g,"")})});var l=i("#billing_iscomp");l.length&&!l.prop("checked")||(n(),e()),i(document.body).on("change","#billing_country, #billing_iscomp",function(){var l,o=i("#billing_iscomp");!o.length||o.prop("checked")?(n(),e()):(i(".woolab-ic-dic-toggle").slideUp(),l="SK"==i("#billing_country").val()?"billing_dic_dph":"billing_dic",i("#billing_company, #billing_ic, #billing_dic, #billing_dic_dph").each(function(e,n){n.setAttribute("data-value",n.value),n.id==l&&n.value.length&&i(document.body).trigger("update_checkout"),n.value=""}))}),i("#billing_dic, #billing_dic_dph").donetyping(function(){var l=i("#billing_country").val();"SK"!=l&&"billing_dic"==this.id&&i(document.body).trigger("update_checkout"),"SK"==l&&"billing_dic_dph"==this.id&&i(document.body).trigger("update_checkout")},750)})}(jQuery);
\ No newline at end of file
+"use strict";!function(i){var l="";function e(){var e;switch(woolab.ares_fill&&(i(".woolab-ic-dic-tip").remove(),c()),i("#billing_ic_field").slideDown(),i("#billing_dic_field").slideDown(),i("#billing_country").val()){case"SK":i("#billing_dic_dph_field").slideDown(),i("#billing_dic_field > label").addClass("woolab-ic-dic-required");break;case"CZ":i("#billing_dic_dph_field").slideUp(),i("#billing_dic_field > label").removeClass("woolab-ic-dic-required");break;default:i("#billing_dic_dph_field").slideUp(),i("#billing_dic_field > label").removeClass("woolab-ic-dic-required")}woolab.ares_check&&(t(e=i("#billing_ic")),i(document.body).on("focusin","#billing_ic",function(){l=e.val()}),e.donetyping(function(){(e=i("#billing_ic")).val()!==l&&t(e)},500)),i("#billing_company_field").slideDown()}function o(){var l="SK"==i("#billing_country").val()?"billing_dic_dph":"billing_dic";i("#billing_company, #billing_ic, #billing_dic, #billing_dic_dph").each(function(e,o){o.getAttribute("data-value")&&(o.value=o.getAttribute("data-value"),o.id==l&&o.value.length&&i(document.body).trigger("update_checkout"))})}function n(i){i.removeClass("kbnt-wrong").removeClass("woocommerce-invalid")}function a(i){i.addClass("kbnt-wrong").addClass("woocommerce-invalid").removeClass("woocommerce-validated")}function c(){i("#billing_company").removeAttr("readonly"),i("#billing_dic").removeAttr("readonly"),i("#billing_postcode").removeAttr("readonly"),i("#billing_city").removeAttr("readonly"),i("#billing_address_1").removeAttr("readonly")}function t(e){if("CZ"===i("#billing_country").val()){var o=e.val();if(o!==l){var t=i("#billing_ic_field"),r='<span role="alert" class="woolab-ic-dic-tip">'+woolab.l18n_not_valid+"</span>";i(".woolab-ic-dic-tip").remove(),n(t),t.removeClass("kbnt-ok").removeClass("woocommerce-validated"),7!=o.length&&8!=o.length||null==o.match(/^[0-9]+$/)?(c(),o.length>0?a(t):n(t)):i.ajax({url:woolab.ajaxurl,data:{action:"ajaxAres",ico:o},beforeSend:function(){t.addClass("kbnt-validating"),t.append('<span role="info" class="woolab-ic-dic-tip">'+woolab.l18n_validating+"</span>")},success:function(l){if(t.removeClass("kbnt-validating"),l)if(0==(l=JSON.parse(l)).error){if(i(".woolab-ic-dic-tip").remove(),t.addClass("kbnt-ok").addClass("woocommerce-validated").removeClass("woocommerce-invalid"),woolab.ares_fill){if(i("#billing_same_as_shipping")&&i("#billing_same_as_shipping").is(":checked")&&window.CollapsibleBlock){document.querySelector("#billing_same_as_shipping").checked=!1;var e=document.querySelector("#woocommerce-billing-fields__field-wrapper");e&&CollapsibleBlock.expand(e);var o=document.querySelector("#fc-expansible-form-section__toggle-plus--billing_company"),n=document.querySelector("#fc-expansible-form-section__content--billing_company");o&&CollapsibleBlock.collapse(o),n&&CollapsibleBlock.expand(n);var a=document.querySelector("#fc-expansible-form-section__toggle-plus--billing_dic"),s=document.querySelector("#fc-expansible-form-section__content--billing_dic");a&&CollapsibleBlock.collapse(a),s&&CollapsibleBlock.expand(s)}i("#billing_company").val(l.spolecnost).attr("readonly",!0),i("#billing_dic").val(l.dic).attr("readonly",!0),i("#billing_address_1").val(l.adresa).attr("readonly",!0),i("#billing_postcode").val(l.psc).attr("readonly",!0),i("#billing_city").val(l.mesto).attr("readonly",!0),t.append('<span role="info" class="woolab-ic-dic-tip">'+woolab.l18n_ok+"</span>"),i("body").trigger("update_checkout")}}else d(t),i(".woolab-ic-dic-tip").length>0&&i(".woolab-ic-dic-tip").remove(),c(),t.append('<span role="alert" class="woolab-ic-dic-tip error">'+l.error+"</span>");else d(t),0==i(".woolab-ic-dic-tip").length&&(c(),t.append(r))},error:function(l){0==i(".woolab-ic-dic-tip").length&&(e.val(""),d(t),t.append('<span role="alert" class="woolab-ic-dic-tip error">'+woolab.l18n_error+"</span>"))}}),l=e.val()}}}function d(l){woolab.ares_fill&&(i("#billing_company").val(""),i("#billing_dic").val(""),i("#billing_postcode").val(""),i("#billing_city").val(""),i("#billing_address_1").val(""),c()),a(l)}i.fn.extend({donetyping:function(l,e){e=e||1e3;var o,n=function(i){o&&(o=null,l.call(i))};return this.each(function(l,a){var c=i(a);c.is(":input")&&i(document.body).on("keyup keypress paste",a,function(i){"keyup"==i.type&&8!=i.keyCode||(o&&clearTimeout(o),o=setTimeout(function(){n(a)},e))}),c.is(":input")&&i(document.body).on("blur",a,function(){n(a)})})}}),i(document).ready(function(){i(document.body).on("input",".woolab-ic-dic-no_spaces input",function(){i(this).val(function(i,l){return l.replace(/\s+/g,"")})});var l=i("#billing_iscomp");l.length&&!l.prop("checked")||(o(),e()),i(document.body).on("change","#billing_country, #billing_iscomp",function(){var l,n=i("#billing_iscomp");!n.length||n.prop("checked")?(o(),e()):(i(".woolab-ic-dic-toggle").slideUp(),l="SK"==i("#billing_country").val()?"billing_dic_dph":"billing_dic",i("#billing_company, #billing_ic, #billing_dic, #billing_dic_dph").each(function(e,o){o.setAttribute("data-value",o.value),o.id==l&&o.value.length&&i(document.body).trigger("update_checkout"),o.value=""}))}),i("#billing_dic, #billing_dic_dph").donetyping(function(){var l=i("#billing_country").val();"SK"!=l&&"billing_dic"==this.id&&i(document.body).trigger("update_checkout"),"SK"==l&&"billing_dic_dph"==this.id&&i(document.body).trigger("update_checkout")},750)})}(jQuery);
\ No newline at end of file
diff --git a/includes/compatibility/fluidcheckout.php b/includes/compatibility/fluidcheckout.php
new file mode 100644
index 0000000..cdeee4d
--- /dev/null
+++ b/includes/compatibility/fluidcheckout.php
@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * Skip hiding optional fields with the "+ add" buttons.
+ * 
+ * @see https://wordpress.org/support/topic/compatibility-with-kybernaut-ico-dic-plugin/#post-17330291
+ */
+function woolab_icdic_fluidcheckout_add_optional_fields_skip_list( $skip_list ) {
+	$skip_list[] = 'billing_ic';
+	$skip_list[] = 'billing_dic';
+	return $skip_list;
+}
+add_filter( 'fc_hide_optional_fields_skip_list', 'woolab_icdic_fluidcheckout_add_optional_fields_skip_list', 10 );
diff --git a/src/js/public.js b/src/js/public.js
index e79a8f5..71bcc04 100644
--- a/src/js/public.js
+++ b/src/js/public.js
@@ -226,9 +226,40 @@
                                 if ( woolab.ares_fill ) {
 
                                     // Compatibility with Fluid Checkout for WooCommerce – Lite
+                                    // https://wordpress.org/support/topic/compatibility-with-kybernaut-ico-dic-plugin/
                                     if ($('#billing_same_as_shipping') && $('#billing_same_as_shipping').is(':checked')) {
-                                        $('#billing_same_as_shipping').click();
-                                        $('#fc-expansible-form-section__toggle-plus--billing_company').click();
+
+                                        // Check whether the CollapsibleBlock library is available
+                                        if ( window.CollapsibleBlock ) {
+
+                                            // Set billing address as different from shipping address
+                                            var fc_billing_same_as_shipping_field = document.querySelector( '#billing_same_as_shipping' );
+                                            fc_billing_same_as_shipping_field.checked = false;
+
+                                            // Expand the billing address fields
+                                            var fc_billing_address_fields_wrapper = document.querySelector( '#woocommerce-billing-fields__field-wrapper' );
+                                            if ( fc_billing_address_fields_wrapper ) {
+                                                CollapsibleBlock.expand( fc_billing_address_fields_wrapper );
+                                            }
+
+                                            // Get company field toggle and content elements
+                                            var fc_billing_company_toggle = document.querySelector( '#fc-expansible-form-section__toggle-plus--billing_company' );
+                                            var fc_billing_company_content = document.querySelector( '#fc-expansible-form-section__content--billing_company' );
+
+                                            // Expand the billing company field
+                                            if ( fc_billing_company_toggle ) { CollapsibleBlock.collapse( fc_billing_company_toggle ); }
+                                            if ( fc_billing_company_content ) { CollapsibleBlock.expand( fc_billing_company_content ); }
+
+                                            // Get dic field toggle and content elements
+                                            var fc_billing_dic_toggle = document.querySelector( '#fc-expansible-form-section__toggle-plus--billing_dic' );
+                                            var fc_billing_dic_content = document.querySelector( '#fc-expansible-form-section__content--billing_dic' );
+
+                                            // Expand the billing dic field
+                                            if ( fc_billing_dic_toggle ) { CollapsibleBlock.collapse( fc_billing_dic_toggle ); }
+                                            if ( fc_billing_dic_content ) { CollapsibleBlock.expand( fc_billing_dic_content ); }
+
+                                        }
+
                                     }
 
                                     // Update values
diff --git a/woolab-ic-dic.php b/woolab-ic-dic.php
index cb08ad1..2321281 100644
--- a/woolab-ic-dic.php
+++ b/woolab-ic-dic.php
@@ -82,6 +82,7 @@ function woolab_icdic_plugin_admin_notice() {
 		// Compatibility
 		include_once( WOOLAB_IC_DIC_ABSPATH . 'includes/compatibility/superfaktura.php');
 		include_once( WOOLAB_IC_DIC_ABSPATH . 'includes/compatibility/pdf-invoices-and-packing-slips-for-woocommerce.php');
+		// include_once( WOOLAB_IC_DIC_ABSPATH . 'includes/compatibility/fluidcheckout.php'); don't apply globally.
 
 		add_filter( 'woocommerce_billing_fields' , 'woolab_icdic_billing_fields', 10, 2 );
 		add_filter( 'woocommerce_checkout_fields', 'woolab_icdic_checkout_fields', 10, 2);