Applying for change of employment early

[kirik8]

Hello,

I'm on Tier 2 General and I know I will be switching employers. My current visa lasts till 28th of May, however I want to apply early in case there are some errors in the application / typos / clerical error etc, so I'll have enough time to reapply in things go wrong.

My new employer has already completed RLMT and is flexible on the starting date of unrestricted CoS (it hasn't been issued yet).

Can I apply now for the role that starts on 28th of May? If yes, will my current visa be valid until that time?
Or, if I apply now, does CoS need to start from the point of application (or some proximity to it)?
Does RLMT have an expiration period? The vacancy advertised didn't contain any specific dates.

Thanks for your advice.

[kirik8]

I think I found the answer in the policy guidance https://www.gov.uk/government/uploads/s ... 1_2015.pdf eventually. In case it is useful to anybody:

When to apply
192.You must apply within three months from the date your Certificate of Sponsorship was
assigned. You must also apply no more than three months before the start date on your
Certificate of Sponsorship. If this is not possible, you should contact your sponsor.
193.If you are applying from inside the UK, you should apply before your current leave expi