Linnworks could definitely be improved in this respect, automatic invoicing for FBA orders is something we are struggling with at the moment. Pish-Pash, what did you use to get Access to automate this?.
To be honest, it's not easy...I had to learn Access from scratch ...& also VBA (& I'm no coder...more of a kludger!) to allow the import raw data into Access, then give sequential VAT numbers (trickier than you might first think, because once imported into Access 'multi item' orders are spread over successive rows, therefore you have to use VBA to examine the order ID & see if it's the same as the last row's Order ID etc).
To create an invoice in Access is a real ordeal (& there are no easily understandable tutorials anywhere - certainly none that met our invoice needs...it took me about 4 weeks of intensive study, taking a bit from this tutorial, a bit from that tutorial, asking on Access forums blah blah.).
Auto Emailing the invoices within Access isn't as tough as creating them (though still not a breeze), & it needs a lot of effort to work out what to do & then code it (e.g. if the subsource = Amazon.de, then an email containing a VAT invoice, is sent in German, Amazon.fr ...it's sent in French etc.)
Linnworks is great but IMHO can't be used at all for VAT invoicing...also as I type, there's a LW issue where - following Amazon's recent hike to £20 for free postage - amazon have changed the way they calculate/show orders..now on Amazon FBA orders, quite often you see a 'shipping charge', but also a 'promo rebate' which cancels the shipping out...meaning the customer actually paid no shipping. Linnworks doesn't 'see' the promo rebate, so a LOT of Amazon Invoices are completely wrong (at the moment, we are having to hack these manually in Access until they issue a fix -
http://www.linnsystems.com/supportforum/viewtopic.php?f=9&t=6054 ).
It's annoyances like these, that made me go the way of my own Access database. i'm so pleased I did, because - without realizing at the time I made the decision - it's subsequently allowed me to be very efficient at doing whatever I need to do with my data - e.g. stock prediction for ordering from my Asian supplier? No problem, Deciding on what items to send to Amazon warehouses? No problem (before these tasks used to take me yonks). Track zero rated orders for VAT returns? Easy etc etc....