NOC certificate a must for applying a dependant visa Tier 2

Hi

My wife's company is applying for a Tier 2 UK visa for her. I am showing myself as a dependant in the visa, BUT her company is telling that I have to get a NOC from my company just to apply for the visa.

My question is how can one company give NOC to a employee before resigning? and

Is the NOC really important for applying for the visa?

It's been observed that when an employer takes onus of Tier 2 immigration application on behalf of the employee (and his dependants), an NOC from the employer of (an employed) dependant is requested ... even though there is no requirement for any such document.

It is evident that arranging any such document from an employer will make the employer aware that the employee intends to leave employment in the immediate / near future. It is also generally understood (by British overseas posts) that an applicant would not want to inform the employer of such intention or resign from the job before a visa is granted - hence any such document is not asked for unless the dependant is applying for a visitor visa to visit a UK-based migrant. In such case (visitor visa application), it is expected that the employee submits a letter from employer that the employee has been granted (temporary) leave and will be resuming employment on expiry of leave.

One may consider applying for self through the employer, and for the dependant(s) on his own. But this may have a financial impact for the migrant if the sponsoring employer is paying for dependant application.