Before following this guide ensure that your account is enabled to submit EC Sales Lists per: Submit a VAT Return / EC Sale List online to HMRC
Navigate to Settings > Configure system > Toggle features.
Select the VAT & bank import tool link on the left hand side and click on the tick box beside the Reverse charge & EC rates toggle.
Once toggled on, you are provided with a VAT treatment drop-down on sales invoices, supplier bills and any other transaction that carries VAT. This not only enables you to define UK VAT transactions but also the sales and purchases of goods and services to/from the EU and outside the EU.
Generating sales of goods or services to EU (business) customers will generate entries on the EC Sales list.
Before generating any sales invoices to your EU business customers, navigate to Contacts > Customers and Edit their details to ensure that their Invoice address stipulates their country and that their Other information shows their EU VAT number.
Once you have generated sales the EC sales list report is accessible from Reports > All reports
Pick the relevant quarter or month, then click the Go button.
The customers' sales details, for inclusion on the return, will be displayed.
Edit Goods sales to identify any Triangulated sales and, once happy with the report click on the Submit to HMRC button.
Note: previous EC Sales submissions can be viewed via the same Reports > All reports screen.