Essentials Bag
A personal overnight bag with documents, meds, and a few days of clothes that travels with you, not the truck.
An essentials bag is the personal suitcase each person keeps on them throughout a move, treated like carry-on luggage on a flight. It holds what you cannot risk losing or living without: passports and IDs, the lease or closing documents, medication, chargers, valuables, and two or three days of clothing and toiletries.
The difference between an essentials bag and an open-first box is who needs it. The open-first box serves the household at the new place; the essentials bag serves you personally and travels in your own vehicle, never on the moving truck. If the truck is delayed, lost, or your stuff sits in storage for days on a long-distance move, the essentials bag is what keeps you functioning.
Pack it the night before the move and keep it physically separate from everything being loaded. On a long-distance move where belongings can travel for a week, the essentials bag effectively becomes your luggage until your boxes arrive.