Notice Period with Previous Odd Job Employer

A friend of mine was working full-time as a sales assistant (odd job) for a company on a graduate visa. He then found a job in his field with a skilled visa sponsor.

The problem is that we had not notified his current employer that he was leaving the company where he worked as a sales assistant. And after receiving the visa, he notified them that he is leaving because he is changing jobs & visa, to which the company responded that you had to notify us a month in advance so that we could arrange for another resource, and you cannot leave like this.

He spoke with the new employee, and they delayed his start date by a month.

But now the issue is that his skilled work visa has already started this week, despite the fact that he has not yet joined the new company. Can he still serve his notice period with his previous employer? Will this present a problem for him, or will he be able to explain the situation when it is raised by the Home Office?

His new employer should notify the Home Office through SMS that his start date has been delayed due to working his notice period. All good thereafter and nothing to worry about.

And if they move the start date after April 4th on sms, the new minimum pay threshold will take effect, and the employer will be required to increase the salary as well?

No, the assignment date of the COS sets the salary thresholds and SOC in play