Can two people sign a recommendation letter?

[psychapplicant21]

I am working as a research assistant and my PI is a Senior Lecturer and Consultant Psychiatrist but the chief investigator of the study is a professor and more well known in the field. However, I have much more contact with my PI than the CI. The CI is also very busy and I'm not sure if he would have time to submit my recommendation letters.

I was going to ask if the CI could co sign the recommendation letter but I wasn't sure if this is allowed?

Edited May 2, 2019 by ccc333

[psychology_student_]

co-signing isn't a thing don't do that. you can certainly ask them each for a LOR though

[psyche132]

I had two recommendation letters that were co-signed. I am attending this fall! 

[psychapplicant21]

1 hour ago, psyche132 said:

I had two recommendation letters that were co-signed. I am attending this fall! 

Thanks I didn't think it would be an issue as it is normal I guess to work on a project with two people, if anything it is an endorsement for what the main person is writing about you.

Edited May 2, 2019 by ccc333

[topsailpsych]

I had two professors write a letter together and co-sign, because I had only taken one short class with each professor so neither felt they knew me well enough to write a letter independently, but together the felt that could comprehensively address my performance as a student.  I was accepted into 4 programs with that as one of my letters, so I don't think it's a problem.

[Tulsa]

Got a co-signed letter and am attending this fall. That should work fine.

[youngqueerliving]

My supervisors are husband and wife and co-founders of our lab, so they co-wrote and co-signed my letter. It only counts as one letter, though, so make sure you still have two other letters.

[chopper.wife]

Also got a co-signed letter that was primarily penned by the more established supervisor but a postdoc also contributed to it.