When entering purchase reverse charge transactions there are 2 scenarios:

1.) Where box 6 should not be updated with the amounts (UK Local Reverse charges, aka Postponed Import VAT accounting (PIVA))

2.) Where box 6 should be updated with the amounts (Overseas Purchases, buying services from abroad)

Therefore the suggestion is: To have ‘sales tax codes’ mapped to box 6 actually update the total for box 6 when it comes from a purchasing transaction (SERIES 4 or 12) to accommodate functionality for ‘Reverse charge’ taxes for Overseas.