diff --git a/application/Espo/Core/Currency/ConfigDataProvider.php b/application/Espo/Core/Currency/ConfigDataProvider.php
index 4e95293816..d69c373f43 100644
--- a/application/Espo/Core/Currency/ConfigDataProvider.php
+++ b/application/Espo/Core/Currency/ConfigDataProvider.php
@@ -101,6 +101,6 @@ class ConfigDataProvider
 
         $rates[$this->getBaseCurrency()] = 1.0;
 
-        return Rates::fromArray($rates);
+        return Rates::fromArray($rates, $this->getBaseCurrency());
     }
 }
diff --git a/application/Espo/Core/Currency/Rates.php b/application/Espo/Core/Currency/Rates.php
index bac2fb9ba9..c1fbe06a84 100644
--- a/application/Espo/Core/Currency/Rates.php
+++ b/application/Espo/Core/Currency/Rates.php
@@ -36,20 +36,45 @@ use RuntimeException;
  */
 class Rates
 {
+    private ?string $baseCode = null;
+
     /**
      * @var array<string,float>
      */
     private array $data = [];
 
-    private function __construct()
+    private function __construct(?string $baseCode = null)
     {
+        $this->baseCode = $baseCode;
     }
 
-    public static function create(): self
+    /**
+     * Create an instance.
+     *
+     * @param ?string $baseCode A base-currency code.
+     */
+    public static function create(?string $baseCode = null): self
     {
-        return new self();
+        return new self($baseCode);
     }
 
+    /**
+     * Get a base-currency code.
+     *
+     * @throws RuntimeException If the base code is not set.
+     */
+    public function getBase(): string
+    {
+        if ($this->baseCode === null) {
+            throw new RuntimeException("Base code is not set.");
+        }
+
+        return $this->baseCode;
+    }
+
+    /**
+     * Clone with a rate value for a specific currency.
+     */
     public function withRate(string $code, float $value): self
     {
         $obj = clone $this;
@@ -58,11 +83,17 @@ class Rates
         return $obj;
     }
 
+    /**
+     * Whether a rate is set for a specific currency.
+     */
     public function hasRate(string $code): bool
     {
         return array_key_exists($code, $this->data);
     }
 
+    /**
+     * Get a rate value for a specific currency.
+     */
     public function getRate(string $code): float
     {
         if (!$this->hasRate($code)) {
@@ -75,10 +106,9 @@ class Rates
     /**
      * @param array<string,float> $data
      */
-    public static function fromArray(array $data): self
+    public static function fromArray(array $data, ?string $baseCode = null): self
     {
-        $obj = new self();
-
+        $obj = new self($baseCode);
         $obj->data = $data;
 
         return $obj;
diff --git a/tests/unit/Espo/Core/Currency/RatesTest.php b/tests/unit/Espo/Core/Currency/RatesTest.php
new file mode 100644
index 0000000000..4ce38e6c15
--- /dev/null
+++ b/tests/unit/Espo/Core/Currency/RatesTest.php
@@ -0,0 +1,46 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM - Open Source CRM application.
+ * Copyright (C) 2014-2022 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
+ * Website: https://www.espocrm.com
+ *
+ * EspoCRM is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EspoCRM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace tests\unit\Espo\Core\Currency;
+
+use Espo\Core\Currency\Rates;
+
+class RatesTest extends \PHPUnit\Framework\TestCase
+{
+    public function testRates1()
+    {
+        $rates = Rates
+            ::create('USD')
+            ->withRate('EUR', 1.2);
+
+        $this->assertEquals('USD', $rates->getBase());
+        $this->assertEquals(true, $rates->hasRate('EUR'));
+        $this->assertEquals(1.2, $rates->getRate('EUR'));
+    }
+}