Just a heads up (& this has been slightly noted in another post with Canadian codes), but Avalara doesn't work with any 3 character country codes, except USA. So...if you are on version 2015 or later & all the country codes are populated in Country Code Maintenance by Sage, those will not work with Avalara. And, to add to this, if you have CRM integrated, it uses the 2 character Alternate Country Code to sync to CRM, so if there is a new country code added to match to Avalara, but doesn't have the correct CRM alternate code, it will stop your CRM sync.
I have contacted Avalara & told them this is an issue & they need to fix it. They are only submitting as an ""enhancement request"". However, I don't see how Avalara is saying their program is still compatible with Sage 2015 or later because all of these country codes are in native Sage as 3 characters, so Avalara should be formatting their program to be compatible or using the 2 character alternate code in Country Code Maintenance as the conversion. If it can work for 3 characters for USA, why not the rest?
And, if there is a 3 character code used in Sales Order, Avalara reports back a bad data error, which then zeroes out the Non-Taxable & Taxable amounts on the SO_SalesOrderHeader & SO_SalesOrderHistoryHeader because it doesn't know which one it should be. So, your history records will have zero Header totals or only the Freight amount as the Header total, which doesn't match the Lines total correctly.
Sage is aware of this & has a KB article as well, saying that after 2015, Avalara, UPS, & FedEx have an issue with 3 characters, but nobody seems to be stepping up to fix it.