[SUPlVBPMa]

I was unaware that they check dimensions too.

They most certainly do.

As said, checking/documenting weights & dimensions Is for payment purposes. They'll charge freight on whatever Is the greater of the two- weight or volume.

What if the label is prepaid? Wouldn't the weight and dimensions already be included in the label if that were the case, since those values already had to be specified (I assume) when making the prepaid label on the carrier's website? I assume that even if the label specifies a certain weight, they still weigh the parcel again once it reaches their warehouse, right?

I'm just trying to figure out if it is necessary to add weight to a parcel when using the tracking ID method.