As part of trivial benefits we are giving amazon vouchers to our employees.
We are on flat rate scheme. Is this a reverse charge?
When filling the VAT return do we fill in the boxes 1 & 4 (cancelling out the VAT impact effectively) or do we add these to box 2 and end up paying VAT on them?
This would be down to the supplier normally. Please check the invoice they issue to you which would normally state the VAT rate, if applicable. However, as @FaradayKeynes mentions, with the flat rate scheme you wouldn’t normally be able to reclaim the VAT paid.