This will depend on your country of residence: if you live outside
of the European Union then it may be possible. It's standard practice
for UK's retailers to include VAT in their ticket price for an item.
Travellers (as of 2011) from outside of the EU, should be able to
claim a refund for VAT added to goods they purchased in the EU (if
the goods are to be exported outside of the EU). The amount of VAT
added to goods sold inside of the EU changes from nation to nation.
Likewise each nation may have a different minimum purchase amount,
that restricts which goods are VAT reclaimable. When shopping online
for shoes in the UK, most checkout systems should automatically
calculate whether you can purchase the shoes tax free when you enter
your shipping destination (if it is outside of the UK/EU).