There are several white varieties listed on this website
https://www.hydrangeasplus.com/category-s/110.htm?searching=Y&sort=7&cat=110&show=30&page=3
have a look and see which is the best match.

Thanks for that Sbg great site shame its in the US. Found a couple of possibilities but still not 100% sure. Hope the label will turn up somewhere in the garden when I’m not looking for it.

The closest I could see was Hydrangea Magical Anouk. The picotee edge was the same as yours. Very pretty.

Many thanks Thorneyside for your help that’s it H. Magical Anouk. As you say it is a very pretty Hydrangea very large blooms and the picotee edging. Once again thank you.

glad you found it. I selected it as it had great pictures. often just seeing the name makes me go 'ah yes that's it'. memory is such a funny thing haha.

Agree with you about the memory Sbg but have to say the older I get the slower it is to register some things. However, in this case it did’nt let me down thank goodness. I’ve attached one of those copper labels to it this time so unless I have a senior moment and prune the branch that has label attached (haha) it should be okay. Once again thanks for your help.