Have seen 10 species local to me so far in my west London suburbs walking area: Small, Green-veined & Large White, Brimstone, Orange Tip, Speckled Wood, Holly Blue, Peacock, Comma & Small Tortoiseshell.
Most obvious omission seems to be Red Admiral. Remember last year saw none until nearly half way through the year when they became quite widespread. This suggests that locally at least little over-wintering & later sightings from migrants that then bred locally.
It's going to be frustrating not being able to visit the chalk around London/north Surrey over the next few weeks to see some of the specialities.