Tier 1 General Extension

[meks99]

Please, I have got some questions regarding extending my visa. I will appreciate it if I can get the answers from here.

Current status:
1. Tier 1 General: Jun 20, 2008 to Feb 10, 2012 (3 Years, 7months, 20 days)
2. Old passport: Jul 06, 2005 to Jul 06, 2010
3. Current Password: Mar 22, 2010 to Mar 21, 2015

Questions:
1. In my initial Tier1 application, I was given more than 3 years, does this matter?

2. In website, its stated that applicant should ensure its last 1 month before applying for extension. Does it matter if I apply now or before the last 1 month?

3. For instance If apply now, will I get additional 2 years to make it at least 5 years on Tier1? Or will they give me 1 year + 3months considering I was initially given 3years + 7months. The issue I am having is that if they give me 1yr + 3months, it won't make it a total of 5 years because I haven't completed the 3yrs + 7months initially given.

4. I will be applying at the same time with my wife and 2 kids(2 yrs and 8 months old). Do my dependents need to send in separate applications? Or can I just include their names in the main applicant's form? If I include them in my form, do I still have to pay for their application fee, especially the kids?

5. My old and expired passport contains the Tier1 visa. Does it matter that my new passport does not have the current visa yet?

I apologies for the long questions but I will greatly appreciate your kind answers. Thanks.