Just to clarify..I think this is an immature White-fronted Goose. 'Albifrons' is the only likely race.
Greylag can be ruled out on the tail pattern..would show more white on the tail and inner tail band. The wings and rump would be much paler too.
As I already stated, a Bean Goose adult or immature would have an orange bill and this bird has a pink bill. There would also be more black at the base of the bill and tip (as already stated by others).
In flight the mantle/rump looks dark, good for White-fronted, as they are usually a little pale and browner in Bean.
Also seems to have white primary shafts, which is good for White-fronted, whereas Bean doesn't. This bird also appears to have very pale primary-coverts, which is another feature of White-fronted.
Don't suppose you got any pics of the 3 suspected Greylags?