Temu purchases

In principle, you can (I have also made purchases there). But you have to be careful.

Much of the material on Temu is of questionable quality. Their business model is primarily to collect data (and then use and sell it) in exchange for dirt-cheap offers. Compared to other online shops, shipping takes much longer (but of course you don't pay anything for it).If you are registered on Temu as a private person (without a vAT number), you will receive a proof of purchase (it is not called an invoice) by email, incl. 21% VAT. It states the order date, the billing address, the delivery address, the payment date and the total amount (incl. VAT). This is followed by a summary of all items (with a photo, title of the item and the amount per item).
In that case, the VAT has already been paid (but you cannot recover it, even if you are not VAT exempted). You can, however, claim the VAT as expenses. The proof of purchase does not state anywhere whether Temu has a branch in the EU or not.

If you register on Temu as a company (with your vAT number), you will receive a proof of purchase by email (it is not called an invoice), but I have no experience with this. If Temu has a branch in the EU, it will normally charge 0% vAT (because it is an intra-Community purchase). If this is not the case, it is a purchase outside the EU and you must pay the total amount (including shipping, import duties and taxes) to Temu.
In the case of an intra-Community purchase, you must include the purchase in your vAT declaration and repay the vAT (normally 21%) back to the Belgian vAT authorities before the 20th of the month following the purchase (even if the goods have not yet been received). If you are exempted from VAT, you do not have to file a monthly (or quarterly) vAT declaration, but in that case you must file a vAT declaration 629 before the 20th of April, July, October or December and repay the vAT amount due to the Belgian vAT authorities by the same day.
For non-EU purchases, you do not have to pay VAT (and you cannot deduct it either).

Johan