The question is then asked, "OK — what if I pack a box, but don't seal it up until the mover can inspect it?" The concern then for the mover is the durability and integrity of the boxes you are using. Are they used? What's their strength rating? As you can see, asking a mover to accept responsibility for a box the mover did not provide or pack can be problematic.
And for heavy stuff, think small boxes: you may think a large box is better for big, heavy items, but the opposite is true. Many of our ProMovers say you'd be surprised how many people fill large boxes until they weigh so much that they break. That slows the process down.
If the contents are not prone to breakage, such as books or paper files, then it may be worth it to pack these items on your own. It's still important to use sturdy boxes and strong packing tape, since these boxes must travel with the rest of your household goods in the moving van. Other items you can likely safely pack yourself include sheets, pillows, blankets and towels – but remember that these are also just the sort of things you can use to cushion fairly durable items in other boxes you pack. Just keep in mind that once you go down that road, your mover will be unlikely to agree to accept responsibility for damage at your destination for goods
A related tip is to not include valuables such as jewelry or currency in a box you do pack – if these items end up missing for some reason, they would not be listed on the inventory, so the mover would not be liable. It's always better to take jewelry and cash with you, or send them separately by an insured tracking service.
Finally, if the mover does not accept the packing that you have done, they may demand that it be repacked or that they be allowed to pack the contents, both of which can affect your costs.
From the American Moving & Storage Association
The American Moving & Storage Association frequently gets asked how consumers who hire a full-service mover can save money, and more specifically, whether they can do so by packing some items ahead of time. The short answer is yes, but with an important exception — make sure the contents are not fragile.
Here's why: when a mover transports your household goods, they become responsible for lost or damaged items, but if the mover did not pack a box (or watch you do so), the mover has no idea how the contents were packed and protected. Therefore the mover can't be expected to be at fault if the contents are damaged during shipping.