I just came back from London Heathrow. Travelex charged me £10 for processing. I requested to get £ back, since if I get other currency, likely there is exchange difference charged by Travelex. For credit card refund, it would depend on when the process is done and the exchange rate at that point in time (or whether your credit card charge additional fees for foreign exchange).
Thanks for your response gg.leigh! [emoji173]️[emoji173]️ So is that mean £10 for all the processing fees no matter how many VAT refund you planning to get back? Let say If I have a total 3 items for VAT, the processing fees are still £10? If £10 that's all they gona charge us I prefer to get the cash back on the spot.