I am travelling to the UK then France and Switzerland. I have set up an appointment with the UK visa office first, based on available guidelines. I am travelling with my wife and 2 kids. Do we need a cover letter for each one?
My brother, his wife and their 2 kids are going with us. Will it be good to have a single cover letter for all of us? Can we have 2 cover letters, one for each family, and mention the 8 names to ensure we all get treated as a single application?
My brother has the necessary funds. He is in the family business and hence I'm also submitting the bank statements and registration of our business. Would a cover letter from my eldest brother for him to confirm that he has access to additional funds if required help?
I am travelling with my wife and 2 kids. Do we need a cover letter for each one?
No. If a cover letter is needed it should be provided as part of the primary's application. Applications are 'linked up' by having the primary give the GWF numbers of all the dependants in the remarks section of their application. Correspondingly, each dependant application should give the primary's GWF number in their application.
Can we have 2 cover letters, one for each family, and mention the 8 names to ensure we all get treated as a single application?
No. Those who have a license from UKVI can make group applications (e.g., tour operators) and others need to make separate applications. So, in your case, each primary should address the circumstances for their dependants separately. It is fine, however, for each primary to state that two families are planning a joint holiday. In this case, the primaries remarks section should include the GWF number of the other primary.
It is okay to provide names, as long as they have the GWF numbers along side of them. Names alone invite the possibility for confusion or some other kind of mix-up.
Would a cover letter from my eldest brother for him to confirm that he has access to additional funds if required help?
Not really. It is your brother's responsibility to submit evidence that he has sole, uncontested access to those funds, and that the provenance of those funds are clearly visible. This makes repeating the same information in a cover letter redundant.