Three patterns cover nearly every move:
1. The weekend gap
Out Friday, in Monday. Most removal firms will hold a loaded lorry or trailer over a weekend for a fee, which beats unloading into a unit and out again two days later. Ask for "overnight hold" before booking anything else.
2. The one-to-three month gap
The classic broken-chain stay. A 75 sq ft unit at the UK average is about £205.50 a month; add cover and two van days, or pay the removers for a double-handle into their own store. Get the double-handle quote: removers' storage often beats self storage once their lorry is already loaded.
3. The partial move
Downsizing or renovating into the new place. Store the second-tier things (books, seasonal kit, the spare room) and move light. This is where per-box collection shines: £7.95 a box a month, collected before completion day, returned room by room once the dust settles.
Dates matter more than price
Book storage for longer than the gap you expect. Completions slip; a unit booked by the week is cheap to extend, but a lorry hold is not. And keep the kettle, the documents and a week of clothes out of storage entirely, in the car, where the chain cannot touch them.