Obtaining Letter of Support from Colleagues External to University for P&T I am planning to apply for tenure and promotion to Associate Professor this Fall 2018.

In our institution, it is not required to obtain the external letter of support for the application towards tenure and promotion to Associate Professor level.

However, it is required for the promotion from Associate Professor to Full Professor. I was told that when an associate professor applies for the promotion to Full Professor, the candidate need to take an electronic copy of the whole P&amp;T file, then colleagues external to the University will be contacted and provided the electronic P&amp;T file towards obtaining  their letter of support. 

However, I am thinking if it would be prudent to obtain external letter of support and attach it along with my tenure and promotion to associate professor application file.

I have already took PDF of the whole P&amp;T file. I am wondering if it would 
be OK to upload the P&amp;T PDF file to Google drive and provide the link to the file in the Google drive to  the colleagues external to the University towards the letter of support.

Please advise.
You can request the letter but I would recommend that the request be directly sent by and returned to the chair of the department or the chair of the departmental P&amp;T tenure committee. They can then decide if it should be attached to the P&amp;T file.

As far as sharing it via Google Drive or equivalent services, I would suggest that you investigate if your institution has a designated file transfer service and use that instead. Your P&amp;T file is probably not something you would want to have "leaked."