Hi Ashleigh1, 

Oh pants - (accounting technical term). 

I have just gone through all the transactions once more, and have realised that the items appearing in Box 7 have been coded as Exempt, in error.  I have switched them over to No Vat, and low and behold, everything works just fine.  

My bad ... and hangover from trying to sort the VAT out too late last night !

Thanks for your help anyway, and apologies

J1