CoS by old passport/ Visa application by new passport

[soso928]

I will receive a Tier 2 CoS from my future employer soon using the details of my old passport. I plan to renew my passport soon for my Tier 2 visa application as my old passport is expiring. The passport no. of my visa application will then be different than that used for the CoS application - will this cause any problem if I submit both passports in my visa application process?

[soso928]

I forgot to mention I am applying outside from UK.

[iworker]

you are suppose to submit all previous passports anyway.
It maybe worth asking your employer to add a note to your cos in the sms. they cant alter the cos, but can add the notes anytime they want.