When entering purchase invoices, Manu Online will sometimes show a different total to the suppliers invoice. The difference is small and is due to different rounding methodologies. The reason is that different computer systems follow different rounding rules but both methods are acceptable and neither is incorrect. The way to handle this is to add a "rounding line" to the invoice.
Below is an example reported to us by one of our customers. The vendor invoice was had 215.51 tax but Manu Online showed 215.52
Manu Online uses what might be called "ERP rounding" where VAT is calculated on the line, rounded and then summed. The vendor is using what might be called "Shop rounding" where Vat is calculated on the total invoice value and then rounded. In this case, the difference between these two methodologies is 0.01.
Our understanding is that both of these methods are accepted by the relevant tax authorities. Unfortunately this is the way the world works. If it is is required to get these to match (as it would be for purchase invoice entry) then the procedure is to add a rounding line to the invoice entry.