TIER1 renewal question regarding address

[vivekmang]

I have been working as a consultant these days. When I apply for my TIER1 extension I have to put in an address where I am currently residing. While my TIER1 renewal is being processed (which in my estimate is taking like 2 months) suppose if I have to move to a different city/address how is that going to work out ?
I mean like am i supposed to update the TIER1 authorities of my new address and where would they mail all the notices and my passport and documents (assuming I moved to a new address) ?

Another related question is my TIER1 currently expires in March 2013. So after I file for an extension will it be ok to work for an employer beyond March 2013 ?

[selva]

I have been working as a consultant these days. When I apply for my TIER1 extension I have to put in an address where I am currently residing. While my TIER1 renewal is being processed (which in my estimate is taking like 2 months) suppose if I have to move to a different city/address how is that going to work out ?
I mean like am i supposed to update the TIER1 authorities of my new address and where would they mail all the notices and my passport and documents (assuming I moved to a new address) ?

Another related question is my TIER1 currently expires in March 2013. So after I file for an extension will it be ok to work for an employer beyond March 2013 ?

There is an address on the application form to inform home office about any changes.

Yes, you can work, your status would be same as before applying for extension (make sure you apply before visa expires).