Help Tier 2 dependent visa Original COS expired

Hi all, thanks for taking a look at my case, any advice appreciated!

So here is the situation:
My partner holds a valid T2 visa, and I, originally held a T2 visa as well, would like to apply for Tier 2 dependent visa reliant on my partner, as my work contract ended.
The question is, does my partner needs to ask his employer issue a new COS since the old one based on which he applied his current T2 visa, is more than 3 months old and should be considered 'expired'? Or could we just fill in the form using his old COS details?

Also another question is, if we apply on ourselves, suggesting the old COS is still good to use, would his employer be notified by Home Office and be mad? Would it be good to inform his employer first that i will be added as a dependent?

Thanks all for help!

My partner holds a valid T2 visa, and I, originally held a T2 visa as well, would like to apply for Tier 2 dependent visa reliant on my partner, as my work contract ended.

Married, unmarried??? You had a visa or you still have a visa?? When does your partners visa expire?

The question is, does my partner needs to ask his employer issue a new COS since the old one based on which he applied his current T2 visa, is more than 3 months old and should be considered 'expired'? Or could we just fill in the form using his old COS details?

No. You simply use the existing details of his visa etc for a dependent visa.

Also another question is, if we apply on ourselves, suggesting the old COS is still good to use, would his employer be notified by Home Office and be mad?

No. Not sure why you think they would be mad. You are dependent on your PARNTER and not on the employer.

Would it be good to inform his employer first that i will be added as a dependent?

Irrelevant.

Hi @CR001, thank you so much for the clarification. I'm still having a visa now but due to some reason I will lose it soon. I just want to make sure that his employer doens't need to be notified as it's pretty stressful time now as he has just changed his employment and we don't want to bother his employer too much before he settles in.

Also, i understand that for unmarried partners, it's required to show proof of relationship dating back to at least two years ago. But is it also a requirement for married couple (married for not long) whose relationship is less than 24 months (about 21 months)? Would 24- month be a cut regardless?

Thanks.

I just want to make sure that his employer doens't need to be notified as it's pretty stressful time now as he has just changed his employment and we don't want to bother his employer too much before he settles in.

They don't. You are overthinking.

Also, i understand that for unmarried partners, it's required to show proof of relationship dating back to at least two years ago. But is it also a requirement for married couple (married for not long) whose relationship is less than 24 months (about 21 months)? Would 24- month be a cut regardless?

It is for unmarried partners. For married couples, you need to prove subsisting relationship and can still submit evidence to prove this, since marriage and living together.

Thank you so much CR001!