It's beautiful. I can't really see what it is. Perhaps Yellow Archangel? In any case it's most likely a native UK wildflower so why not let it spread. It will surely attract insects or bees. There is no such thing as a weed really. They are wild plants which we need for biodiversity and we shouldn't hurry to pull them up and plant non-native species.
Very nice too! A lot of our native plants are pretty and easy to care for. They attract pollinators ad suffer few problems. I have ox-eye daisies, field marigolds and cornflowers everywhere this year.
Thank you I'll try and dig it out and replant it somewhere in the garden rather than at the side of the shed where it can't be seen. It is rather pretty.
If you can it would be best to ty to include a large lump of soil with it so as to minimise disruption to the roots then fill the hole with soil from elsewhere. Perhaps dig the reception hole first and use the soil from there. A good idea would be to put the plant in a plastic bag while you transport it so that bits of soil do not drop off the underneath while you are moving it, even if the moving is only a short distance.