Thank you for your enquiry.
Yes as along as the application is sent in before the expiry.
While the decision is being made, an applicant continues to have the same status as they had until a decision is made so long as they sent their application prior to the expiry.
It is a general rule in UK immigration law
I understand. If you made your application through a lawyer they will be able to confirm your application is valid. But if you sent it yourself, employers are so nervous and it is best to get a Certificate of Application. Your employer has an option to ring the Home Office's hotline to get confirmation. You can find the number by googling it.
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