Unfortunately I’m not sure I understand the question. I need more information in order to point you in the right direction.
You say that you “credit customers for warranty” – what does this mean? Do you mean that you’re crediting customers for the value of goods returned or do you give customers refunds under some sort of insurance based warranty?
The EC sales list and the Intrastat don’t always match because the sales list is for sales while the Intrastat is for the movement of goods, but I can’t tell from the information you’ve provided how this would be affected by your warranty credits.
If you can give me some further information I’ll try to help.
Marie