It is common practise for Business to Business sites to show prices exclusive of VAT as most businesses will reclaim any VAT on their purchases.
Shopfront is by default configured to show all prices for logged in B2B users to be exclusive of VAT. This can be altered if required.
If your site is also set up for B2C ecommerce then it will depend who your target customers are for B2C on how you set up pricing for these customers. If the B2C customers will mostly be businesses without a sales ledger account then Shopfront should be configured to show B2C prices as VAT exclusive. If the majority of customers are domestic then VAT inclusive pricing will make more sense.
If VAT inclusive pricing is used VAT will only be included if the delivery address for the order is within the EU. Most Shopfront installations have the default delivery address as the UK but that will change to the customers default delivery address once they login.