VAT & Import Duty

My mom recently shipped 3 boxes from the US.  She put $130 value on one box and $100 value on the two other boxes.  We got charged VAT on one of the $100 boxes but not on the other or the $130 box.  We had to pay VAT on the one box that had pictures & a picture frame listed on the contents (one of the $100 boxes which was about 5 times what the frame was actually worth - but that's my mom for you.  She ALWAYS screws us over with VAT and import duty by guessing too high a value), but not on the one that listed china, or the one that listed just pictures.  Does anyone have any idea how it works?  Do you only have to pay VAT on certain items but not others?  It just really doesn't make sense to have to pay VAT on a picture frame valued at $100 and not on china valued at $130.

Did she mark the boxes as personal items? AFAIK, you don't need to pay duty on personal items being shipped to you.

Unfortunately they do often charge for VAT on personal items. I have found the best way to do it is to have the sender put a value under $50 and write unsolicited gift on it several times.

Also, if you call them and explain to them that it was a personal item, they may cancel the invoice.  I've had to do that twice.  Both times, I ended up not owing anything