TN Question

Hi there, how many time can one renew and work for the same company with TNN visa.

Not sure if there is a limit, but I did it for 4 years with the same organization (then moved back home).

There really is no limit, however, I was advised by the company I work for who has sponsored me from TN to H1B and now in greencard process, that after 4 or 5yrs of TN, they do get suspicious if you truly are "temporary." After my 5th renewal of TN my company transfered me to H1B to avoid that concern.

don't know if you have gathered your needed info yet gthava,
but I offer the following:
(I am presently on my second TN-status)

whupwhup states a very widely held belief, that after some number of "renewals" you will inevitably hit a USBP officer who will question how temporary you are.

However, all of the laws, treaties, memos, etc, state there is no limit on the number of times you can receive TN-status.
There is a subtlety here: notice I put "renewal" in quotes, and then stopped using it.Technically you don't renew TN-status.
You apply again.
This can make the logistics of the employer letter of offer tricky. The employer's letter must make it very clear that they are only offering you a temporary position of no more then 1 year. And then on 'renewal' they need to phase the further offer as equally temporary. This can run you afoul of HR bureaucrats in your company because you will inevitably go to 'renew' your TN at an earlier date each year (because it can't lapse even for a day). Good luck. Dealing with getting a properly phrased employer letter has been my biggest challenge.