After working as an educator at the court in Ansbach, he moved to London in 1752 to take up the post of pastor of the German Reformed congregation. He became assistant librarian at the British Museum in 1758, reader and tutor to Queen Charlotte in the 1760s and was elected as a Fellow of the Royal Society in 1770. Several of his daughters worked as governesses at court or in noble families. His son Joseph Planta succeeded him at the British Museum and later became its principal librarian.
