Guys - just been checking and updating the costs for International Small Packet Signed For with Extra Insurance compensation up to £500.

Going from UK to USA:

The actual cost for 400g is £10.67
I add £0.50 for packing/handling
Then I expect to see a total of £11.17

What I actually get is £13.17

Any idea where this additional £2.00 has come from please?

The International Small Packet Signed For compensation up to £36 option weighing 400g comes back with the price I expect of £8.47 plus £0.50 = £8.97.

As ever, thank you in advance for any advice.