I thought Bank of Scotland and Halifax and Lloyds were once license but despite NafWest being owned by RBS there are separate licenses for each part of that group.
There are implications from the licensing on FSCS claims. In the event you had say £80,000 in NatWest and £80,000 in RBS if the RBS group (i.e. NatWest and RBS) collapsed your full £160,000 would be protected as both parts of the group are covered by a separate licence.
If say there is one licence covering 2 or 3 banks in the HBOS group then if you had £75K in 3 of their banks you would only be covered to £75K and not the full £225K despite having below the £85K limit in each account.
I have just Googled for evidence of this and http://www.money.co.uk/guides/which-banks-count-as-one-under-the-financial-services-compensation-scheme-fscs.htm gives a simple summary of the main points of the FCSC cover…though FCSC’s own site is more definitive.
Lloyds and BOS are not in fact under one license but HSBC and First Direct are. Here is a list for those interested:
Institutions which covered under a single group licence:
Bank of Ireland UK and Post Office
Bank of Scotland, Aviva, Halifax, Intelligent Finance, Birmingham Midshires (BM Savings), AA, Saga, Capital Bank, St James’s Place Bank
Barclays, Standard Life Cash Savings, The Woolwich
Clydesdale Bank and Yorkshire Bank
The Co-operative Bank, Smile and Britannia
Coventry Building Society and Stroud & Swindon
HSBC and First Direct
Lloyds Bank and Lloyds Bank Private Banking
Nationwide, Cheshire Building Society, Derbyshire Building Society and Dunfermline Building Society
Santander and Cahoot
Skipton Building Society and Scarborough Investments Direct
Yorkshire Building Society, Barnsley Building Society, Chelsea Building Society and Norwich & Peterborough Building Society