Error: This value is already used by another document

When adding a value to your UID field, you may encounter the following error:

This value is already used by another <custom-type-name> document

This means another document in your repository already has this UID value. It could be a document that is drafted or in the archive. If you can't find the document with this UID value, one of your documents used to have this UID value, and now it is locked. To re-assign a UID, you must delete the document that currently has that UID.

This article will explain why an old UID becomes locked and how to unlock it.

Old UID Values

A UID field will save all previous UID values.

We save all the previous UID values of a given document so that your old links won't be broken on your site when you change a UID value.

Because the UID value must be unique, the document can not reuse an old UID value on a different one. You will receive the above error if you try to use an old UID name on a different document.

Preventing an old URL from appearing on your site

To prevent a page from appearing with the old URL, we suggest that you check with each URL to see if the UID received is the current one. If so, load the page; if not, redirect to the current URL.

Finding, removing, & unlocking an old UID value from a document

Let's say you have an old UID value called "old-uid" that you wish to reuse on another document.

To use it again, you need to figure out which document has that value. To do this, go to your API browser (make sure to replace "your-repo-name" with the URL name for your repository):

Then enter the following into the query field, making sure to add the correct Custom Type API ID instead of "your-custom-type":

[at(my.your-custom-type.uid, "old-uid")]

Then search your documents, and the document that contains "old-uid" as a previous UID value should appear.

Note that if your repo uses more than one language, you might need to add the lang parameter to your URL to see the document. After you have performed the search above, add &lang=* to the query URL, load the page, and the result should appear.

Once you've found the document, you need to duplicate it. You can do this by going to the edit page for that document, then clicking on the Duplicate button at the top of the screen.

After you've duplicated it, you can delete the original, and this will allow you to use "old-uid" again.

1 Like

Threads close after a period of inactivity. Flag this thread to re-open it and continue the conversation.


But in my case, I use UIDs as the page paths.
And when I want to add a link in page (A) to point to page (B), I do that by linking the page documents internally (i.e. add a link in page A document pointing to page B document). So if I duplicate and delete the old document of page (B) all the links to page (B) in other documents will be broken.

Also, according to SEO, it is not recommended to have 2 urls serving the same content. Is there any way I can unlock the old UIDs to reuse them without deleting the old page document?

Thanks :slight_smile:

Hello @mahmoud.elbayoumy, Yes. If you delete a document you'd need to re-add the links where you used it. For the moment this is the only workaround to reuse an existing old UID.

Hello @maxime.hersand

Duplicating a document is making a copy of that sole document. Nothing else gets duplicated except that one. In the duplicated version, all content will be the same, including Links to other documents, but these are just references to those docs. It doesn’t mean they get duplicated as well.

We are already tracking it as a feature request for future improvement.

Thanks for pointing this out.


And in the case a document was deleted (not archived), is there a way to free up that UID value?

Hi @stefan.suhani_blondi, Deleting a document automatically frees the use of the reserved UID value.

Hi Pau,

I'm in a situation where performing the above query returns one document but this document is not visible in my Prismic dashboard. What am I supposed to do to free up the UID in that case?

When I go to the document based on the ID, there is a mismatch between the route name and the UID value I want to use. :scream:

Hey @prismic24, I'm not sure why this could be happening. I'll need the following info to try and reproduce it:

  • URL of your repository
  • The query
  • UID and type of the document

For future users that encounter this issue but can't find the document with that uid in the api:

For me, the document returned in in the API didn't have the same uid, but still walking through the steps above on that very document deleted the uid in question. It's like that document had 2 uids.

Hope this helps others that end up in this tricky spot!

1 Like

How do I delete the original? It's only archived and still has the same UID.

Hi @technigo ,

If you visit the archived document you can delete it from there.