If I ask for a bank loan, are they more likely to accept my application if I confirm I have four credit cards, including one of theirs, or am I better not to declare that?
The number of credit cards held will not make a difference, any outstanding balances and any repayments being made each month will be taken into account.
You could always get a copy of your credit record yourself and see exactly what it says on it. But I think your cc's must be on record because my daughter had no cc and therefore no credit record and was advised by a FA to get herself a card and use it for a few months and then apply for a mortgage.