Office Customization Tool: How to Configure and Deploy Microsoft 365 Apps (OCT Guide)
Installing Microsoft Office on one laptop is easy. Installing it on thirty or three hundred machines, with the same apps, the same languages and the same update behavior on every one, is where most teams run into trouble. The Office Customization Tool (OCT) exists to solve that problem. It is Microsoft’s web-based service for building the configuration file that controls how Microsoft 365 Apps are deployed.
This guide explains what the Office Customization Tool is, how it differs from the Office Deployment Tool, and how to use it step by step at config.office.com. You will also learn how to save configurations in the cloud, deploy them, follow best practices, and fix the errors that most often appear.
Quick answer: The Office Customization Tool is a free web service from Microsoft at config.office.com. You choose apps, languages, update settings and preferences, then export a configuration XML file. The Office Deployment Tool (ODT) reads that file and installs Office. There is no separate OCT app to download.
What Is the Office Customization Tool (OCT)?
The Office Customization Tool is a web-based service that creates the configuration files used to deploy Office in large organizations. You open it in a browser at config.office.com, choose the products, languages and application preferences you want, and export the result as a configuration file.
A configuration file gives you control over three broad areas of an Office installation. First, which applications and languages are installed. Second, how those applications are updated. Third, which application preferences are applied, such as default file formats or macro notification behavior.
It is important to understand what OCT does not do. It does not produce a modified installer, and it does not install anything on its own. It produces a configuration XML file. That file is then used by the Office Deployment Tool or another software distribution solution to carry out the installation.
Microsoft announced general availability of the tool in October 2018 as an Azure-based cloud service. Before that, administrators wrote the configuration XML by hand, which was slow and easy to get wrong. Microsoft now recommends using OCT rather than editing the XML in a text editor, because it reduces the chance of errors.
OCT is designed for deployments across many devices. Microsoft describes it as part of the process of installing Office on hundreds or thousands of computers. For most businesses, Microsoft 365 Apps are the core productivity software in daily use, so a repeatable, consistent deployment saves real time for IT teams and reduces support calls for everyone else.
Office Customization Tool vs Office Deployment Tool
The two tools are often confused, and many articles blur the line between them. The simplest way to remember the difference is this: OCT plans the deployment, and ODT carries it out.
| Feature | Office Customization Tool (OCT) | Office Deployment Tool (ODT) |
|---|---|---|
| What it is | A web-based service for building a configuration | A command-line tool for downloading and installing Office |
| Where you find it | config.office.com in your browser | A free download from Microsoft |
| What it produces or does | Produces a configuration XML file | Reads that file and installs or updates Office |
| Who runs it | An IT admin, through a graphical interface | An IT admin, through the command line |
| Cost | Free | Free |
The Office Deployment Tool consists of two parts: setup.exe and a configuration file. You can edit the configuration file by hand, but Microsoft recommends using the Office Customization Tool to create and modify it instead. In other words, you can technically use ODT without OCT, but you cannot use OCT to install Office without ODT or another distribution method.
If you manage devices with Microsoft Configuration Manager, there is a shortcut. Microsoft recommends using the Office 365 Installer wizard in the Configuration Manager console, which includes a customized version of the Office Customization Tool.
Is There an Office Customization Tool Download?
No. Many people search for an Office Customization Tool download, but there is no separate application to install. OCT is entirely web-based, so you use it directly in your browser at Microsoft’s configuration site.
The component you can download is the Office Deployment Tool. Microsoft provides it as a free utility, and it includes setup.exe along with sample XML configuration files. Be cautious with third-party pages that offer an “Office Customization Tool download for Windows”. Use Microsoft’s own site for both OCT and ODT.
Who Should Use the Office Customization Tool?
OCT is best suited to IT administrators and teams that deploy Microsoft 365 Apps to many devices and want every device to look the same. It also helps smaller teams. If you manage dozens of devices, a saved configuration means you build the setup once and reuse it, instead of clicking through the installer on each machine and ending up with slightly different results.
Use OCT if you:
- Deploy Microsoft 365 Apps to many devices at once
- Need the same apps, languages and update behavior on every machine
- Want to preconfigure settings such as default file formats or macro notifications
- Use Configuration Manager, Intune or another tool that can consume the exported file
Skip OCT if you are installing Office on a single personal computer. The standard Microsoft installer is enough in that case. Microsoft itself points individual users to the regular install process.
If your team is also looking at automating repetitive IT and admin work, a standard Office configuration is a good first step, because it removes one more manual task from every new device setup.
What You Can Customize with the Office Customization Tool
The tool is organized into sections. Each section controls a different part of the deployment. The table below summarizes them, using the section names you will see in the tool.
| Setting group | What it controls | Why it matters |
|---|---|---|
| Products and releases | Architecture (32-bit or 64-bit), products, update channel and version | Each configuration file deploys one architecture, so plan separate files if you need both |
| Apps and features | Which Office applications are included | Excluding apps you do not need, such as Access or Publisher, keeps installs smaller and easier to maintain |
| Language | One or more languages, including a Match operating system option | Avoids manual language pack installs after deployment |
| Installation | Install from the cloud (Office CDN) or a local source, whether users see the installation, and whether running apps are shut down | Lets you run quiet installs that do not interrupt users |
| Update and upgrade | Where updates come from, automatic update checks, removal of MSI versions, and automatic architecture upgrade | Keeps update behavior consistent and helps migrate older installs |
| Licensing and activation | License terms, volume license keys where relevant, and activation type: user based, shared computer or device based | Prevents licensing errors after rollout |
| General | Your organization name and a description of the configuration | Helps you recognize the file later, for example a configuration for the finance team |
| Application preferences | Settings such as VBA macro notifications, default file locations and default file formats | Saves post-deployment cleanup because users start with the right defaults |
A few details are worth knowing. The update channel decides how often devices receive new features. Microsoft recommends choosing the latest version unless you need a specific one. For licensing, Microsoft 365 Apps is not volume licensed and does not require KMS or MAK activation, so those key settings only apply if you deploy a volume-licensed version of Office, Visio or Project.
Application preferences can be searched and filtered by Office app, and each setting includes a description. If your sales team lives in Outlook, a consistent Office setup also pairs well with a CRM that integrates with Outlook, since both depend on Outlook behaving the same way on every device.
How to Use the Office Customization Tool: Step-by-Step
The steps below follow the order of the sections in the tool. Add your own screenshots at each stage so readers can see exactly what to select.
Step 1: Open the tool. Go to config.office.com and open the deployment settings. If you want to save and manage your configuration in the cloud, sign in to the Microsoft 365 Apps admin center before you begin.
Step 2: Choose architecture and products. In the Products and releases section, pick the architecture first. Each configuration file can deploy only one architecture. Microsoft generally recommends 64-bit Office for most modern systems, but 32-bit may still be required if you rely on older add-ins or legacy applications. Then choose the products you want to deploy.
Step 3: Choose the update channel and version. The update channel determines how frequently devices receive new features. Match it to how your team handles patching, using the channel names listed in the tool. Unless you need a particular version, choose the latest.
Step 4: Select apps and features. Include only what your users need. Removing unused applications reduces storage and simplifies long-term maintenance.
Step 5: Choose languages. Add your primary language and any secondary ones. You can select Match operating system to install the same languages that are in use on each device.
Warning: There is a known issue where the tool lets you select a language that the product does not support. For example, you can select English (United Kingdom), French (Canada) or Spanish (Mexico) for Project or Visio, but those languages are not supported there. If you do not correct the XML manually, the installation will fail. Check the supported language lists for Visio and Project before you export.
Step 6: Set installation options. Choose whether to install directly from the cloud or from a local source on your network. Decide whether to show the installation to end users, and whether to shut down running applications. Turning off the display gives you a silent install.
Step 7: Set update and upgrade options. Choose whether updates come from the cloud, a local source or Configuration Manager. To update devices automatically, select the Office CDN and the option to check for updates automatically. You can also choose to remove all MSI versions of Office automatically, install the same languages as the removed version, and upgrade the architecture.
Step 8: Set licensing and activation. Choose whether to accept the license terms automatically. For volume-licensed products, enter the appropriate key settings. Then choose how to activate the product: user based, shared computer or device based.
Step 9: Fill in General and Application preferences. Enter your organization name and a description, such as the department the file is for. Then set any application preferences you want applied, such as macro notification behavior or default file formats.
Step 10: Finish and export. Select Finish, review your settings in the right-hand pane, and select Export. Accept the license agreement and name the file. If you are saving the file to the cloud, select Done instead. You can now use the file with the Office Deployment Tool or another distribution solution.
To change an existing configuration later, open the tool, select Import, choose the file, adjust the settings and export it again.
Save and Manage Configuration Files in the Cloud
You can save and manage your deployment configurations in the cloud instead of keeping loose XML files on shared drives. Sign in to the Microsoft 365 Apps admin center and open the Device Configuration page under Customization. From there you can create, edit, copy, upload and download configuration files.
A practical approach is to create a baseline configuration and then copy it for each variation, such as one for finance and one for engineering. The Office Deployment Tool can also refer to cloud-based files directly when you run it.
There is one important limitation. Saving and managing configuration files in the cloud is not available to customers on Office 365 operated by 21Vianet, or on Office 365 GCC, GCC High and DoD plans. If you are on one of those plans, export the file and store it yourself.
How to Deploy Office with Your Configuration File
Once you have exported the file, deploy it with the Office Deployment Tool. Download the tool from Microsoft, run it to extract setup.exe, and place your configuration file in the same folder. Then open a command prompt in that folder.
To download the Office installation files, run:
setup.exe /download configuration.xmlTo install Office using the configuration, run:
setup.exe /configure configuration.xmlIf you set the display option so that users do not see the installation, the install runs silently. The result is the same Office setup on every device: the same apps, the same update channel and the same languages.
You are not limited to ODT. You can use the exported file with Configuration Manager or another software distribution solution. You can also apply application preferences to an existing Microsoft 365 Apps installation without changing any other deployment settings, which is useful when you only want to update defaults such as file formats or macro notifications on devices that are already running Office.
Office Customization Tool Best Practices
A little planning prevents most deployment problems. These practices apply whether you manage thirty devices or three thousand.
- Pilot first. Deploy your configuration to a small group of test devices before rolling it out widely. This surfaces compatibility and configuration problems early.
- Choose the right architecture. Use 64-bit unless your organization depends on legacy add-ins that require 32-bit.
- Match the update channel to your patching approach. Stable channels suit production, while preview channels are better kept for test devices.
- Exclude apps you do not need. Fewer applications mean a smaller install and less to maintain.
- Keep a tested baseline. Reuse a proven configuration instead of rebuilding from scratch. Document how each variation differs, and consider whether process automation consulting could help you turn your deployment steps into a repeatable workflow.
- Prefer OCT to manual XML edits. Microsoft recommends using the tool over a text editor because it reduces errors.
- Keep the ID and Host attributes. The tool adds these attributes to the configuration. They contain no personally identifiable information, and Microsoft uses the values to understand which configurations customers use. They are optional and can be removed without affecting your deployment.
- Use application preferences with security in mind. Setting macro notification behavior is a useful control, but it works best as part of layered security solutions for your business rather than as a single safeguard.
Troubleshooting Common Office Customization Tool Problems
Most problems come from a small number of causes. Use this table to find the likely cause and fix.
| Problem | Likely cause | Fix |
|---|---|---|
| The XML file produces an error at deployment | A manual edit after export, such as a missing bracket or mismatched tag | Open the file in a text editor and check its structure, or re-export a clean file from OCT |
| Installation fails after you selected a language | A language that Project or Visio does not support was selected | Remove the unsupported language or correct the XML, then redeploy |
| Office installs but shows an unlicensed message | The activation method in the configuration does not match your licensing model | Return to Licensing and activation, fix the setting, re-export and redeploy |
| Users see update prompts nobody approved | The update channel delivers updates sooner than you intended | Change to a more conservative update channel and push the updated configuration |
| An older add-in crashes or stops working on 64-bit Office | The add-in only supports 32-bit Office | Regenerate the configuration with 32-bit selected and test again |
If a deployment keeps failing after you have checked these causes, a short technical consultation can help you find what is different about your environment.
Frequently Asked Questions
What is the Office Customization Tool used for?
It is used to build a configuration file for deploying Microsoft 365 Apps. You choose the apps, languages, update settings, licensing and preferences, then export an XML file that the Office Deployment Tool uses to install Office consistently across devices.
Is the Office Customization Tool free?
Yes. Microsoft provides OCT as a free web-based service, and the Office Deployment Tool is also a free download. You still need valid Microsoft 365 licensing to use the Office products you deploy.
Is there an Office Customization Tool download?
No. OCT runs in your browser at config.office.com, so there is nothing to install. The downloadable piece is the Office Deployment Tool, which includes setup.exe and sample configuration files.
Do I need the Office Deployment Tool if I use OCT?
You need either ODT or another software distribution solution. OCT only creates the configuration. Something else, such as ODT or Configuration Manager, must download and install Office using that file.
Can I use OCT for Office 2019 or Office 2021?
OCT works best with Microsoft 365 Apps that use Click-to-Run. Guidance from third parties indicates it can generate a configuration for perpetual versions such as Office 2019 or 2021, but without full parity, and update channel settings in particular behave differently. Always verify the result against Microsoft’s current documentation before relying on it.
Can I edit the XML by hand after exporting?
You can, and Microsoft documents the schema, but any formatting error will break the deployment. Microsoft recommends using the Office Customization Tool instead of a text editor. If you do edit manually, check the file carefully before you run setup.
Should I choose 32-bit or 64-bit Office?
Microsoft generally recommends 64-bit Office for most modern systems. Choose 32-bit only if you rely on older add-ins or legacy applications that do not support 64-bit.
Can I save configuration files in the cloud?
Yes, through the Microsoft 365 Apps admin center, on the Device Configuration page under Customization. This is not available to customers on Office 365 operated by 21Vianet, or on Office 365 GCC, GCC High and DoD plans.
Conclusion
The Office Customization Tool plans your Office deployment, and the Office Deployment Tool carries it out. Both are free, and together they give you the same apps, languages and update behavior on every device, with fewer support calls and a setup you can repeat without guessing what ended up on each machine.
Start with a pilot group, build a clean baseline, save it in the cloud if your plan allows, and reuse it. If you would like help planning a rollout or tidying up the systems around it, you can book a call with The Cloud Republic team.
