White School shirt long sleeved age 14 or over (Kennington SE11)

Looking for white long sleeves school uniform shirt age 14 or bigger, Boys' or Girls ' not important. I am a size 12/14 adult and using these for a work uniform, they are great as do not crease and wash easily. i might not do this job for long and saving for a room so rather use recycled than 'invest' and bin after a few days. Can collect any time. . Not interested in cream linen blouses sorry. Any other help appreciated!