Display customer's store credit balance in header - sample header.phtml file for Magento 1.9.2.2 base/default theme.

header.phtml

<?php
/**
 * Magento
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Academic Free License (AFL 3.0)
 * that is bundled with this package in the file LICENSE_AFL.txt.
 * It is also available through the world-wide-web at this URL:
 * http://opensource.org/licenses/afl-3.0.php
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@magento.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade Magento to newer
 * versions in the future. If you wish to customize Magento for your
 * needs please refer to http://www.magento.com for more information.
 *
 * @category    design
 * @package     base_default
 * @copyright   Copyright (c) 2006-2015 X.commerce, Inc. (http://www.magento.com)
 * @license     http://opensource.org/licenses/afl-3.0.php  Academic Free License (AFL 3.0)
 */
/**
 * @var Mage_Page_Block_Html_Header $this
 */

/* BEGIN magecredit.com store credit balance code 1/2 */
if (Mage::helper('core')->isModuleEnabled("Wf_CustomerBalance")) {
    $currentCustomerId = Mage::getSingleton('customer/session')->getCustomerId();
    if ($currentCustomerId) {
        $currentWebsiteId = Mage::app()->getWebsite()->getId();
        $balance = Mage::getModel('wf_customerbalance/balance')
            ->setCustomerId($currentCustomerId)
            ->setWebsiteId($currentWebsiteId)
            ->loadByCustomer();
        $_balanceFormatted = Mage::helper('core')->currency($balance->getAmount(), true, false);
    } else {
        $_balanceFormatted = "";
    }
} else {
    $_balanceFormatted = "";
}
/* END magecredit.com store credit balance code 1/2 */
?>
<div class="header-container">
    <div class="header">
        <?php if ($this->getIsHomePage()):?>
        <h1 class="logo"><strong><?php echo $this->getLogoAlt() ?></strong><a href="<?php echo $this->getUrl('') ?>" title="<?php echo $this->getLogoAlt() ?>" class="logo"><img src="<?php echo $this->getLogoSrc() ?>" alt="<?php echo $this->getLogoAlt() ?>" /></a></h1>
        <?php else:?>
        <a href="<?php echo $this->getUrl('') ?>" title="<?php echo $this->getLogoAlt() ?>" class="logo"><strong><?php echo $this->getLogoAlt() ?></strong><img src="<?php echo $this->getLogoSrc() ?>" alt="<?php echo $this->getLogoAlt() ?>" /></a>
        <?php endif?>
        <div class="quick-access">
            <?php echo $this->getChildHtml('topSearch') ?>
            <p class="welcome-msg">
            <?php echo $this->getChildHtml('welcome') ?> <?php echo $this->getAdditionalHtml() ?>
            
            <?php /* BEGIN magecredit.com store credit balance code 2/2 */ ?>
            <?php if (Mage::getSingleton('customer/session')->isLoggedIn()): ?>
                <?php echo $this->__("Credit Balance:"); ?>
                <a href="<?php echo $this->getUrl('storecredit/info'); ?>">
                    <?php echo $_balanceFormatted; ?>
                </a>
            <?php endif; ?>
            <?php /* END magecredit.com store credit balance code 2/2 */ ?>

            </p>
            <?php echo $this->getChildHtml('topLinks') ?>
            <?php echo $this->getChildHtml('store_language') ?>
        </div>
        <?php echo $this->getChildHtml('topContainer'); ?>
    </div>
</div>
<?php echo $this->getChildHtml('topMenu') ?>