What it means
The file is inside the EPUB, but content.opf does not list it in the book's file inventory. EPUB readers and validators use that inventory to decide which chapters, images, styles, fonts, and navigation files belong to the book.
EPUB error guide
OPF_003 item is not declared in the OPF manifest
How to understand the OPF_003 EPUBCheck error when a file exists in the EPUB but is missing from the OPF manifest, and when a manifest repair is safe before KDP upload.
Direct answer
Short answer for this EPUB error.
Use this summary before the detailed guide. Most KDP, Kindle Previewer, and EPUBCheck messages still need the affected file path inside the EPUB before you edit anything.
Can EPUB Fixer repair it?
EPUB Fixer can treat this as repairable when the extra file is clearly used by the book and has a known media type, such as a referenced image, CSS file, XHTML content document, nav file, NCX file, or font. A safe repair adds a manifest item with a stable id, correct href, and correct media-type, then revalidates the EPUB.
What to check next
Copy the exact file path from the EPUBCheck message. Example: if it reports OEBPS/styles/print.css, keep that folder and file name exactly as written.
What not to assume
The tool should not add every loose file to the manifest automatically. Draft files, source files, backups, hidden system files, duplicate images, or unrelated assets may be better removed from the package. If the file is not referenced by the book and its purpose is unclear, the report should stop for manual review.
Error text
OPF_003: Item exists in the EPUB, but is not declared in the OPF manifest.
When you usually see it
EPUBCheck, Kindle Previewer, or KDP finds a packaged file such as an XHTML chapter, image, stylesheet, font, nav file, or NCX file that is present in the ZIP container but missing from the OPF manifest.
Plain English
What it means inside the EPUB.
The file is inside the EPUB, but content.opf does not list it in the book's file inventory. EPUB readers and validators use that inventory to decide which chapters, images, styles, fonts, and navigation files belong to the book.
This often happens after manual ZIP edits, image replacement, stylesheet cleanup, chapter renaming, or export tools that leave unused files behind. It can also happen when a file is copied into the EPUB after export but no matching manifest item is added to content.opf.
User checklist
Follow this repair path before another upload.
Work through the file path, the real EPUB contents, and the add-or-remove decision in order. Stop when the next step would require guessing what the author meant.
- 1Copy the exact file path from the EPUBCheck message. Example: if it reports OEBPS/styles/print.css, keep that folder and file name exactly as written.
- 2Open the EPUB like a ZIP package and check whether that file is really there. If the file is missing, this is not just a manifest problem.
- 3Open content.opf and look for the manifest list. If no item href matches the reported path, the EPUB file inventory is incomplete.
- 4Search the book for the same path before adding it. If an XHTML page, CSS file, nav.xhtml, toc.ncx, cover setting, or metadata entry uses it, the file probably belongs in the manifest.
- 5Choose add or remove. Add it only when the book uses it; remove it when it is a backup, hidden file, duplicate image, source document, or old export leftover.
- 6Validate again after one change. A fixed manifest entry can reveal a second issue, such as the wrong media type or another undeclared file.
Validator context
Why this error matters to validators.
EPUB 3.3 package rules
The OPF package file defines the book metadata, file inventory, reading order, and navigation wiring that validators inspect before a reading system can process the book reliably.
EPUBCheck
EPUBCheck evaluates EPUB 2 and EPUB 3 publications against official EPUB specifications and reports structure, package, markup, and reference problems.
Repairability
Can EPUB Fixer repair it?
Safe repair condition
EPUB Fixer can treat this as repairable when the extra file is clearly used by the book and has a known media type, such as a referenced image, CSS file, XHTML content document, nav file, NCX file, or font. A safe repair adds a manifest item with a stable id, correct href, and correct media-type, then revalidates the EPUB.
When it stops at diagnosis
The tool should not add every loose file to the manifest automatically. Draft files, source files, backups, hidden system files, duplicate images, or unrelated assets may be better removed from the package. If the file is not referenced by the book and its purpose is unclear, the report should stop for manual review.
Before / after example
Before: the EPUB ZIP contains OEBPS/styles/print.css and a chapter references it, but content.opf has no manifest item for that CSS file. After: content.opf includes a manifest item for styles/print.css with text/css as the media type. Before: the ZIP contains old-cover-backup.jpg that no file references; that should not be blindly declared.
Next step
Scan the actual file before editing by hand.
The same error code can come from different files and different causes. Uploading the EPUB lets the report show the affected path and whether the fix is safe to make automatically.
Upload EPUB to scanFAQ
Common questions about this EPUB error.
What does OPF-003 item is not declared in the OPF manifest mean?
It means a file is present inside the EPUB container, but the OPF package file does not list it in the manifest. Validators use the manifest as the official inventory of publication resources.
Should I add every undeclared file to the OPF manifest?
No. Add the file only when it is part of the book and has a clear media type. Backup files, unused images, source files, and hidden system files are usually better removed from the EPUB.
Can OPF-003 block a KDP upload?
Yes. KDP and Kindle Previewer can reject an EPUB when the package inventory does not match the files needed by the book, especially for chapters, images, stylesheets, fonts, navigation files, and NCX files.
How is OPF-003 different from RSC-007?
OPF_003 is about a file that exists in the EPUB but is not declared in the manifest. RSC_007 is usually about a reference to a file path that cannot be found in the EPUB at all.
Can EPUB Fixer repair OPF-003 automatically?
It can classify the issue as repairable when the file is clearly used by the book and the correct manifest media type is known. If the file looks unused or ambiguous, the report should stop for manual review.
How do I know whether to add the file or remove it?
Add it only when an XHTML, CSS, nav, NCX, cover, or metadata reference actually uses it. Remove it when it looks like an old backup, duplicate export file, hidden system file, or source document.
Where is the OPF manifest?
It is inside the OPF package file, often named content.opf or package.opf. The manifest section is the file inventory for the EPUB.