I'm wanting to apply for a French long-stay visa while being in/near France. Is it necessary to return to my country (Australia), or can I go to an embassy in Belgium or some other country closer by?
(I'd be using the 90 days that Australians have to visit the Schengen zone without a visa.)
All the guidelines suggest that because I can't apply while in France that I'd need to return to Australia, but what about another country?
In principle, you are supposed to apply for a long-stay visa before moving to France and you can only do that at the consulate serving the place where you live. You should be asked to submit documentation of your status as a resident (e.g. a residence permit or long-stay visa from the relevant country) together with your application. This applies across the French consular network and should not depend on the consulate where you want to apply (even if what counts as proof of address/residence will).
The rules are specifically designed to prevent what you are contemplating (moving first and applying for a visa afterwards). Thus, if you are a resident in another European country, you do not necessarily need to go back to your country of citizenship to lodge an application but if you are only visiting using the short-stay visa exemption rules, you are not allowed to use a consulate in a neighbouring country to circumvent the requirement to apply from your place of residence.
There are a few exceptions to this principle, allowing you to apply for a long-term status after entering France. If you qualify, you would not apply for a long-stay visa either but skip that and apply directly for a carte de séjour. This would for example be the case if you are married to a French citizen or if you are joining a family member and apply within one month of entering. Note that technically, there is nothing preventing you to apply for a carte de séjour directly even if you don't have a visa long séjour, the préfecture is legally enpowered to make an exception if you can make a case for it (e.g. by arguing that returning to your country would entail unnecessary hardship) but they can obviously refuse.
