Office Settings & Configuration

How to Fix the Custom Dictionary Is Full Error in Word for Mac

WPS Editor Sep 28, 2026 869 views

Question details

The user is unable to add new words to their custom dictionary in Word for Mac because the application throws an error stating that the custom dictionary is full.

How to Fix the Custom Dictionary Is Full Error in Word for Mac

Product: Microsoft Word for Mac
Device & OS: Mac
Scenario: Adding language-specific or custom terms to the dictionary while spell checking a document.
Observed behavior: Word displays a message indicating the custom dictionary is full, preventing any new word entries from being saved, though existing dictionaries remain intact even after changing Office subscriptions.

Before you start

Before editing or replacing any dictionary files, it is highly recommended to locate and back up your current custom dictionary file to avoid accidentally losing your previously saved words.

Solution 1Recommended

Remove Unnecessary Entries from the Custom Dictionary

Clear out old or incorrectly spelled words from your custom dictionary to free up space for new entries.

By manually editing your custom dictionary, you can delete unwanted words and resolve the full capacity error without losing your entire custom word list.

Open Word Preferences

Launch Microsoft Word on your Mac. Click on 'Word' in the top Apple menu bar, then select 'Preferences'.

Access Proofing Tools

In the Word Preferences window, locate the 'Authoring and Proofing Tools' section and click on 'Spelling & Grammar'.

Open Custom Dictionaries

Click the 'Dictionaries...' button to open the Custom Dictionaries dialog box.

Edit the Dictionary File

Select your active dictionary (usually named 'Custom Dictionary') from the list and click 'Edit'. If prompted, confirm that Word will stop checking spelling while you edit.

Delete Unwanted Words

The dictionary will open as a text document. Delete any unnecessary or outdated words from the list, then save and close the document.

Remove Unnecessary Entries from the Custom Dictionary

Office Upgrades and Subscriptions: If you are upgrading to Microsoft 365 or reinstalling Office, your existing custom dictionaries are generally retained and will not be deleted automatically.

Solution 2

Create a New Custom Dictionary

Instead of deleting words, you can create a fresh custom dictionary to bypass the storage limit of the current one.

Free Microsoft Office alternative

Try WPS Office for a Seamless and Error-Free Writing Experience

Tired of managing full dictionaries and complex configuration errors in Word for Mac? WPS Office offers a completely free, lightweight, and highly compatible alternative with a built-in spell checker and simple dictionary management tools.

1. Download WPS Office: Visit the official WPS Office website and download the Mac version for free.
2. Install the Application: Open the downloaded installer file and follow the on-screen prompts to install WPS Office on your Mac.
3. Open Your Word Documents: Launch WPS Writer and open your existing .docx files to start writing and spell checking without interruptions.

Fully compatible with Microsoft Word (.docx) formats, ensuring your documents look perfect.Built-in intelligent spell check with easy-to-use custom dictionary management.Lightweight application that runs smoothly and efficiently on Mac devices.Free to use with a familiar, user-friendly interface that requires no learning curve.

Frequently Asked Questions

Where is the custom dictionary file located on a Mac?

In Office for Mac, custom dictionaries are typically stored in the hidden Library folder. You can usually find them by navigating to ~/Library/Group Containers/UBF8T346G9.Office/Custom Dictionary in Finder.

Will upgrading to Microsoft 365 delete my custom dictionary?

No, switching your Office subscription to Microsoft 365 or changing Office installations generally does not delete existing entries. However, backing up your dictionary file is always recommended before making installation changes.

Is there a word limit for custom dictionaries in Word?

Yes, older versions and certain formats of custom dictionaries in Word can hit a file size or word count limit, which triggers the 'dictionary is full' error. Creating a new supplementary dictionary is a common workaround.

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