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Project Key Underscore



We are currently experimenting with Project Keys and want to add underscores in them. 

We found that this is possible and should be working. However when we add a underscore to a new project, we get the following error:

Project keys must start with an uppercase letter, followed by one or more uppercase alphanumeric characters.

Is there a way to get rid of this and get the underscore to work? 






2 answers

1 accepted

1 vote
Answer accepted

The pattern is regulated by a regular expression in Admin -> General -> Advanced.

But don't change it - there are some "interesting" things (i.e. stuff breaks) that happen when a project key is not the standard.  Stick with A-Z as the first character and then A-Z,0-9 for the next 1 to 9.

Hi @Nic Brough _Adaptavist_,

thanks for this answer. Currently this is set to: 



Is is posible to add the underscores which we want as a extra? What i mean is the following: Is everything between the [] and in front of the + default? 


So right now we are able to add projects:


If this is the case, can we change the setting to: 


(Added the _)


Correction: Can I change it to: ([A-Z][A-Z_0-9]+)


I found it here:


But i want to know how big the chance is that we break existing things. We currently do not have a lot of issues and will use the new keys in new projects only.

I'm not great with regex, but I think it's a bit more simple

[A-Z][A-Z0-9]+  will work fine

[A-Z][A-Z0-9_]+  will allow underscores and break some things (Mostly Apps to be fair - you won't have any problems in Jira)

We've just added the _ and it's working!

Thanks :) 

Like Tor Magne Svendsen likes this

On the "breaking existing stuff" - you're fine.  The regex is only used to stop you creating projects with dodgy keys, you won't have any problem with existing projects or new ones that still match the old pattern.

Like Mitch Wiemans likes this

Hi @Mitch Wiemans

my answer doesnt answer your question but...

Just a question! You have the choice of ~24 letters and 0-9 numbers with max 10char key, plus the combinations!

Why you want to make it this way? Why you just not stick to the pattern of the system? I think it saves a lot of troubles later :D 

Best regards


hi @Christos Moysiadis,


we will be making a project for each country and each type of system.

For example:

Netherlands system named Test using system Test 2 will be:


For out Service Desk this would make a lot of sence :)




It could be made easier as i see. if you want my advice something like that could be possible

For Netherlands as you said:

Country letters as prefix -> NL or DE for Germany

1) For Software : key = NLSOFT or DESOFT

2) For Service D. : key = NLSD or DESD

3) For Business : key = NLB or DEB

how about this ? just an opinion ;)



Hi Chris, 


I like the way you think :) We had the same exact ideas. However there should be 1 extra tag which is the name. Let's say a car name Volkswagon.

Tag will be: NLVWSOFT (Netherlands, Software, Volkswagon)

We will use this method if the underscore is not posible. But if it is....

NLVWSOFT     = Hard to read quick

NL_VW_SOFT  = Easy to read quick

How did you get on this this? I have the same issue and have a naming convention but want the issue keys to be easy to read but I also have geographic area, department and project area to add e.g. Australia, Operations, Issue Management:



I really want to put in the underscores but am nervous!


Hi Louise, 


I solved this problem as followed. 


Right now we have project which we can make as followed:


  • AA_BB


So we can have some text, an underscore, and some text (as much as we want).


In order to achieve this you have to be logged in as an administrator. 

Navigate to: Settings -> System and select Advanced Settings.

In the advanced settings menu you have to search for: jira.projectkey.pattern

I have changed the values to: ([A-Z][A-Z_0-9]+) . This allowed us to start a project with 1 or more letters. Then another letter or _ or number


Please let me know if this helps!


Kind Regards,


Yes, that's the same as the original answer, but you missed off "it is not recommended to do this as it can break some apps" (plus make it harder to migrate to Cloud, as you'll need to re-key the project before exporting it)

Don't be nervous.  I changed mine on my server years ago to allow underscores and never once had an issue.

However, now that I'm migrating to Cloud I'm fuming that I am losing this flexibility.  YMMV.

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