If you are UK VAT registered, Startershop can calculate the VAT totals on your invoice (we do this by assuming that the prices in the store are VAT inclusive).
If you are UK VAT registered and you sell items for which VAT is not charged at a standard rate (lower rate or zero rated), then Startershop cannot calculate your VAT for you at this time. Please contact us to discuss your requirements, as we may develop the features to deal with this if there is enough interest.
If you do not know what UK VAT registration is, then you are probably not VAT registered. However, if you are unsure we recommend that you seek professional advice.