diff --git a/addons/barcodes_gs1_nomenclature/static/src/js/barcode_parser.js b/addons/barcodes_gs1_nomenclature/static/src/js/barcode_parser.js
index 29b6b9d22e9..2c6f447098a 100644
--- a/addons/barcodes_gs1_nomenclature/static/src/js/barcode_parser.js
+++ b/addons/barcodes_gs1_nomenclature/static/src/js/barcode_parser.js
@@ -22,6 +22,13 @@ patch(BarcodeParser, {
 });
 
 patch(BarcodeParser.prototype, {
+    setup(attributes) {
+        super.setup(...arguments);
+        // Use the nomenclature's separaor regex, else use an impossible one.
+        const nomenclatureSeparator = this.nomenclature && this.nomenclature.gs1_separator_fnc1;
+        this.gs1SeparatorRegex = new RegExp(nomenclatureSeparator || '.^', 'g');
+    },
+
     /**
      * Convert YYMMDD GS1 date into a Date object
      *
@@ -106,7 +113,8 @@ patch(BarcodeParser.prototype, {
     gs1_decompose_extanded(barcode) {
         const results = [];
         const rules = this.nomenclature.rules.filter(rule => rule.encoding === 'gs1-128');
-        const separatorReg = FNC1_CHAR + "?";
+        const separatorReg = `(?:${FNC1_CHAR}+)?`;
+        barcode = this._convertGS1Separators(barcode);
 
         while (barcode.length > 0) {
             const barcodeLength = barcode.length;
@@ -143,4 +151,17 @@ patch(BarcodeParser.prototype, {
         }
         return super.parse_barcode(...arguments);
     },
+
+    /**
+     * The FNC1 is the default GS1 separator character, but through the field `gs1_separator_fnc1`,
+     * the user has the possibility to define one or multiple characters to use as separator as
+     * a regex. This method replaces all of the matches in the given barcode by the FNC1.
+     *
+     * @param {string} barcode
+     * @returns {string}
+     */
+    _convertGS1Separators: function (barcode) {
+        barcode = barcode.replace(this.gs1SeparatorRegex, FNC1_CHAR);
+        return barcode;
+    },
 });
diff --git a/addons/barcodes_gs1_nomenclature/static/src/js/tests/barcode_parser_tests.js b/addons/barcodes_gs1_nomenclature/static/src/js/tests/barcode_parser_tests.js
index d563f6c27c0..9490d912ca3 100644
--- a/addons/barcodes_gs1_nomenclature/static/src/js/tests/barcode_parser_tests.js
+++ b/addons/barcodes_gs1_nomenclature/static/src/js/tests/barcode_parser_tests.js
@@ -224,7 +224,8 @@ QUnit.module('Barcode GS1 Parser', {
 
     QUnit.test('Test Alternative GS1 Separator (fnc1)', async function (assert) {
         assert.expect(6);
-        const barcodeNomenclature = new BarcodeParser({nomenclature: this.nomenclature});
+        let barcodeNomenclature = new BarcodeParser({ nomenclature: this.nomenclature });
+        await barcodeNomenclature.loaded;
 
         // (21)12345(15)090101(16)100101
         const code128 = "2112345#1509010116100101";
@@ -238,7 +239,10 @@ QUnit.module('Barcode GS1 Parser', {
             );
         }
 
-        barcodeService.gs1SeparatorRegex = '#';
+        // Reload the nomenclature but this time using '#' as separator.
+        this.nomenclature.gs1_separator_fnc1 = '#';
+        barcodeNomenclature = new BarcodeParser({ nomenclature: this.nomenclature });
+        await barcodeNomenclature.loaded;
         res = barcodeNomenclature.gs1_decompose_extanded(barcodeService.cleanBarcode(code128));
         assert.equal(res.length, 3);
         assert.equal(res[0].ai, "21");