On 5 July 1942, Margot received a call-up to report for labour camp in Germany. She was among the first group of Jews in the Netherlands to be summoned. Her parents did not want her to go, but those who did not go, were arrested. Otto and Edith had anticipated the call-up and had planned to go into hiding in the hiding place Otto had set up in the annex of his business premises on 16 July 1942. Because of Margot's call-up, they advanced their move.
They left their home the morning after the call-up. They told their subtenant that they were going to Switzerland.
A few days later, Anne wrote about being in hiding in her diary.
‘Of course we are not allowed to look out of the window at all or go outside. Also we have to do everything softly in case they hear us below.’
The Frank family were helped by six of Otto’s employees and friends. The people working in the ground floor warehouse knew nothing about the hiding place, except for the father of helper Bep Voskuijl. As the warehouse manager, he was well-placed to keep an eye on things.