diff --git a/src/Spout/Writer/Common/Internal/AbstractWorkbook.php b/src/Spout/Writer/Common/Internal/AbstractWorkbook.php
index c8f9f9f..ca16a29 100644
--- a/src/Spout/Writer/Common/Internal/AbstractWorkbook.php
+++ b/src/Spout/Writer/Common/Internal/AbstractWorkbook.php
@@ -167,6 +167,11 @@ abstract class AbstractWorkbook implements WorkbookInterface
         }
     }
 
+    public function applyStyleToCurrentWorksheet($style) {
+        $updatedStyle = $styleHelper->applyExtraStylesIfNeeded($style, array());
+        $registeredStyle = $styleHelper->registerStyle($updatedStyle);
+    }
+
     /**
      * @return bool Whether the current worksheet has reached the maximum number of rows per sheet.
      */
diff --git a/src/Spout/Writer/Style/Style.php b/src/Spout/Writer/Style/Style.php
index 91e9475..a4254d7 100644
--- a/src/Spout/Writer/Style/Style.php
+++ b/src/Spout/Writer/Style/Style.php
@@ -61,6 +61,13 @@ class Style
     /** @var bool Whether the wrap text property was set */
     protected $hasSetWrapText = false;
 
+    /** @var string Custom number format */
+    protected $numberFormat = '';
+    /** @var boolean Whether specific number format has been set */
+    protected $hasSetNumberFormat = false;
+    /** @var integer Holds the number format id */
+    protected $numberFormatId = 0;
+
     /**
      * @return int|null
      */
@@ -243,6 +250,35 @@ class Style
         return $this->shouldApplyFont;
     }
 
+    public function setNumberFormat($format)
+    {
+        $this->numberFormat = $format;
+        $this->hasSetNumberFormat = true;
+        return $this;
+    }
+
+    public function setNumberFormatId($id)
+    {
+        $this->numberFormatId = $id;
+    }
+
+
+    public function shouldApplyNumberFormat()
+    {
+        return $this->hasSetNumberFormat;
+    }
+
+    public function getNumberFormatId()
+    {
+        return $this->numberFormatId;
+    }
+
+    public function getNumberFormat()
+    {
+        return $this->numberFormat;
+    }
+
+
     /**
      * Serializes the style for future comparison with other styles.
      * The ID is excluded from the comparison, as we only care about
diff --git a/src/Spout/Writer/Style/StyleBuilder.php b/src/Spout/Writer/Style/StyleBuilder.php
index 4619f43..8521a1c 100644
--- a/src/Spout/Writer/Style/StyleBuilder.php
+++ b/src/Spout/Writer/Style/StyleBuilder.php
@@ -121,6 +121,12 @@ class StyleBuilder
         return $this;
     }
 
+    public function setNumberFormat($format)
+    {
+        $this->style->setNumberFormat($format);
+        return $this;
+    }
+
     /**
      * Returns the configured style. The style is cached and can be reused.
      *
diff --git a/src/Spout/Writer/XLSX/Helper/StyleHelper.php b/src/Spout/Writer/XLSX/Helper/StyleHelper.php
index f3da2b5..789c72a 100644
--- a/src/Spout/Writer/XLSX/Helper/StyleHelper.php
+++ b/src/Spout/Writer/XLSX/Helper/StyleHelper.php
@@ -25,6 +25,7 @@ class StyleHelper extends AbstractStyleHelper
 <styleSheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
 EOD;
 
+        $content .= $this->getNumberFormatSectionContent();
         $content .= $this->getFontsSectionContent();
         $content .= $this->getFillsSectionContent();
         $content .= $this->getBordersSectionContent();
@@ -39,6 +40,31 @@ EOD;
         return $content;
     }
 
+    protected function getNumberFormatSectionContent() {
+        $formats = array();
+        $numberFormatCount = 0;
+        // This is the limit excel holds for the default number formats
+        $baseNumberFormatId = 163;
+
+        foreach($this->getRegisteredStyles() as $style) {
+            /* If this evals to false we should skip it since it isnt used */
+            if ($style->shouldApplyNumberFormat()) {
+                $numberFormatCount++;
+                $style->setNumberFormatId($baseNumberFormatId + $numberFormatCount);
+                $formats[] = '<numFmt numFmtId="'.$style->getNumberFormatId().'" formatCode="'.$style->getNumberFormat().'"/>';
+            }
+        }
+
+        if ($numberFormatCount == 0){
+            return '';
+        }
+
+        $content = '<numFmts count="'.$numberFormatCount.'">';
+        $content .= implode('', $formats);
+        $content .= '</numFmts>';
+        return $content;
+    }
+
     /**
      * Returns the content of the "<fonts>" section.
      *
@@ -139,7 +165,11 @@ EOD;
         $content = '<cellXfs count="' . count($registeredStyles) . '">';
 
         foreach ($registeredStyles as $style) {
-            $content .= '<xf numFmtId="0" fontId="' . $style->getId() . '" fillId="0" borderId="0" xfId="0"';
+            $content .= '<xf numFmtId="'.$style->getNumberFormatId().'" fontId="' . $style->getId() . '" fillId="0" borderId="0" xfId="0"';
+
+            if ($style->shouldApplyNumberFormat()) {
+                $content .= ' applyNumberFormat="1"';
+            }
 
             if ($style->shouldApplyFont()) {
                 $content .= ' applyFont="1"';
diff --git a/src/Spout/Writer/XLSX/Internal/Workbook.php b/src/Spout/Writer/XLSX/Internal/Workbook.php
index 5208d4f..9b9ab24 100644
--- a/src/Spout/Writer/XLSX/Internal/Workbook.php
+++ b/src/Spout/Writer/XLSX/Internal/Workbook.php
@@ -58,6 +58,10 @@ class Workbook extends AbstractWorkbook
         $this->sharedStringsHelper = new SharedStringsHelper($xlFolder);
     }
 
+    public function registerStyle($style) {
+        $this->styleHelper->registerStyle($style);
+    }
+
     /**
      * @return \Box\Spout\Writer\XLSX\Helper\StyleHelper Helper to apply styles to XLSX files
      */
diff --git a/src/Spout/Writer/XLSX/Internal/Worksheet.php b/src/Spout/Writer/XLSX/Internal/Worksheet.php
index af3fbc4..ab959c6 100644
--- a/src/Spout/Writer/XLSX/Internal/Worksheet.php
+++ b/src/Spout/Writer/XLSX/Internal/Worksheet.php
@@ -133,10 +133,18 @@ EOD;
 
         $rowXML = '<row r="' . $rowIndex . '" spans="1:' . $numCells . '">';
 
-        foreach($dataRow as $cellValue) {
+        foreach($dataRow as $cell) {
+            if (is_array($cell)) {
+                $cellValue = $cell[0];
+                $cellStyle = $cell[1];
+            } else {
+                $cellValue = $cell;
+                $cellStyle = $style;
+            }
+
             $columnIndex = CellHelper::getCellIndexFromColumnIndex($cellNumber);
             $cellXML = '<c r="' . $columnIndex . $rowIndex . '"';
-            $cellXML .= ' s="' . $style->getId() . '"';
+            $cellXML .= ' s="' . $cellStyle->getId() . '"';
 
             if (CellHelper::isNonEmptyString($cellValue)) {
                 if ($this->shouldUseInlineStrings) {
diff --git a/src/Spout/Writer/XLSX/Writer.php b/src/Spout/Writer/XLSX/Writer.php
index 965955a..d61040e 100644
--- a/src/Spout/Writer/XLSX/Writer.php
+++ b/src/Spout/Writer/XLSX/Writer.php
@@ -64,6 +64,10 @@ class Writer extends AbstractMultiSheetsWriter
         return $this;
     }
 
+    public function registerStyle($style) {
+        $this->book->registerStyle($style);
+    }
+
     /**
      * Configures the write and sets the current sheet pointer to a new sheet.
      *