MailMerge 2.5.1

dotnet add package MailMerge --version 2.5.1
NuGet\Install-Package MailMerge -Version 2.5.1
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="MailMerge" Version="2.5.1" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add MailMerge --version 2.5.1
#r "nuget: MailMerge, 2.5.1"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install MailMerge as a Cake Addin
#addin nuget:?package=MailMerge&version=2.5.1

// Install MailMerge as a Cake Tool
#tool nuget:?package=MailMerge&version=2.5.1

MailMerge for docx Documents

MailMerge replaces simple and complex merge fields in WordProcessingML .docx files and helps you apply .Net's Xml & XPath tooling to Word documents.

Component Usage

For Streams:
var (outputStream, errors) = new MailMerger().Merge(inputStream, Dictionary);
For Files:
var (ok,errors) = new MailMerger().Merge(inputFileName, Dictionary, outputFileName);

Set the current DateTime for date merge fields on MailMerger.DateTime, e.g. new MailMerger{DateTime=...}

CommandLine Usage

Merge a docx file:

dotnet MailMerge.dll inputFile1 outputFile1 [inputFileN [...outputFileN]] [ key=value [...] ]
  • example:
dotnet MailMerge.dll MyTemplate.docx MyLetterToBill.docx  FirstName=Bill  "LastName=O Reilly"

Show a document's Xml:

dotnet MailMerge.dll  --showxml file [fileN ...]

Component Extension Methods & Helpers



A NamespaceManager, NameTable & Uri which you need when creating an XmlDocument and/or XElements:

var xdoc = new XmlDocument(OoXmlNamespace.Manager.NameTable)
var xelement= mainDocumentPart.CreateElement("w", "t", OoXmlNamespace.WpML2006MainUri)


None really, but see for settable limits. For commandline --showxml usage in scripts, you'll want to set appsettings.json::Logging.LogLevel to Information or higher

Doesn't do

  • Anything except simple fields, complex fields, DATE, PRINTDATE & SAVEDATE fields
  • Date formatting codes except a b B d D M y & h m s
  • Style/Formatting codes except these Date/Time formats
  • Multi-row datasources, just does 1 row at a time


  • Interprets .Net DateTime formatting codes that aren't in the WordProcessingML spec.


How do I create a Word document with merge fields without attaching a datasource?

Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 is compatible.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed. 
.NET Core netcoreapp3.0 was computed.  netcoreapp3.1 is compatible. 
.NET Standard netstandard2.1 is compatible. 
MonoAndroid monoandroid was computed. 
MonoMac monomac was computed. 
MonoTouch monotouch was computed. 
Tizen tizen60 was computed. 
Xamarin.iOS xamarinios was computed. 
Xamarin.Mac xamarinmac was computed. 
Xamarin.TVOS xamarintvos was computed. 
Xamarin.WatchOS xamarinwatchos was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

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Version Downloads Last updated
2.5.1 40,691 6/9/2023
2.5.0 156 6/9/2023
2.4.0 82,301 11/24/2020
2.3.0 651 7/20/2020
2.2.1 1,389 6/9/2019
2.2.0 1,269 11/24/2018
2.1.0 1,246 3/31/2018
2.0.0 1,137 3/23/2018
1.0.1 1,062 2/27/2018

2.5.1 Fix: Handle mergefields that Word has split across xml elements (@AllTaken)
     2.5.0 Merging an empty field now results in an empty output instead of the merge field being skipped over (@dr-consit)
           Supported targets changed from netcoreapp2 to net6.0;netcoreapp3.1;netstandard2.1
     2.4.0 OoXml Spec requires all fields to be treated CaseInsensitively
     2.3.0 Merges multi-line (\n or \n\r) input fields into a single <w:r>
           Breaking Change: Moved namespace MailMerge.Helpers -> MailMerge
     2.2.1 Should not require the existence of appsettings.json
     2.2.0 Handle more variations of w:instrText sequence.
     2.1.0 Added support for Complex Field Character sequences.
     2.0.0 Renamed component MailMerge.MailMerge to MailMerge.MailMerger