Anyone know what this is, please?

It's definitely a day lily and live up to that name as they only flower for one day but if you remove the old ones you will get constant flowers for a long time. Had these in my last garden and would have a daily wander with a cuppa and snip them off by hand. If you leave the old flowers on, eventually the old flowers are replaced by roundish seed heads which don't look nice and result in less flowers. Rather do the daily deadheading which takes minutes and have repeat flowering

Baggs

Thank you. I thought it might be but I've no direct experience of day lilies.

No, me neither!

Search image with Google lens, * Baggs*.
It's very pretty!!

Looks like a day lily to me too.

Yes, Im pretty sure it's a day lily. Beautiful

Thank you. I thought it might be but I've no direct experience of day lilies.

You could check it on one of those plant identifier apps.

Hemerocallis, Daylilly surely?

It looks like a day lily, some have come up in my garden but they're orange, but I don't remember planting them. Each flower lasts for just one day, apparently.