eBay adding VAT to postage after sale

[shovio]

I started using Simple Delivery recently.  I’ve sold about 10 items with it so far.  Two of the buyers have complained to me that the price of the postage seems to have changed AFTER they bid on the item. 

The latest one is this lot:

https://www.ebay.co.uk/itm/127433743641

The postage price on the listing is £5.99, but the buyer says they are being charged £7.19, which is +20%.  What’s going on here?

[papso22]

Can you ask the buyer to send you a screenshot of where they are being asked to pay the higher amount?

[shovio]

Hi papso. I have messaged the buyer who has now paid anyway. I also checked my orders page and it does indeed show the VAT there. See attached screenshot.

[john1297576]

I bdlieve the VAT is because postage is bought from ebay. 

No VAT if bought at Post Office.

[shovio]

Why do ebay appear to be hiding that fact from buyers?  Have you had anyone query it on your listings?