The first order from a country you have never sold into: what actually changes
The first order from another European country almost always brings a little anxiety, and in most cases the anxiety is out of proportion to what changes.
It is worth separating the real differences from the imagined ones, because they are few and knowing them in advance removes most of the problem.
There is no customs. Shipments between European Union countries do not cross a customs frontier: no declarations, no duties, no holds. From that point of view, shipping to Munich is like shipping to Bolzano.
VAT does not apply, under the reverse charge, when the customer holds a valid VAT number listed in VIES. The check happens at the moment of the order, so it arrives already done.
Transport costs more and takes a few days longer. It is the most concrete operational difference, and it is also why cross-border works better on high-value, low-weight products than on heavy single-use goods.
Language looks like an obstacle and in practice is less of one than expected. Product listings are already translated, the order arrives structured rather than as free text, and the few direct exchanges are settled in English or with a machine translation that handles this kind of content well.
What really changes, and nobody mentions, are expectations.
A German customer takes punctuality for granted and communicates directly: if something is wrong they write it plainly, and that is not hostility. A French customer expects more care in the form of correspondence. In some northern countries it is normal to ask for the tracking number before the confirmation.
These are cultural differences learned in three or four orders, and they require nothing beyond noticing them.
Practically, two things are worth preparing before the order arrives rather than after. A shipping rate for the European zones you cover, so the cost appears to the customer instead of having to be worked out by hand. And packaging suited to a longer journey, because a parcel that survives Milan to Rome will not necessarily survive Milan to Warsaw with more sorting stages.
The rest is identical to a domestic sale: you prepare, you ship, you update the status.
The first foreign order, in short, is mostly a rehearsal of procedure. Once it has passed, the second makes no difference, and your market has suddenly become twenty times larger.
In summary: between EU countries there is no customs and shipping abroad is like shipping to another city, VAT does not apply with the VIES check already done, transport costs and takes longer which favours high-value low-weight products, the real differences are cultural and are learned in a few orders, and shipping rates and packaging are worth preparing beforehand.