In message . com,
" writes

I'm going to be in UK for 1 day plan to use a 3.50 1 day bus and a
1.50 1 way bus fare., do I have to pay 5 pounds or 8 pounds?

A 3.50 bus pass covers all buses in all zones throughout the day (and on
until 4.30 the next morning), so it is unlikely you would also need a
single (1.50 cash) ticket.

Unless you plan to return to London in the near future, it is not really
worth putting the bus pass on Oyster - just get a paper ticket
(available from the same places that you buy Oyster).

If you are planning to visit London again and therefore prefer the
Oyster option, the total would be 6.50 including the 3.00 deposit (which
is refundable).
--
Paul Terry