Visa appointment date may be up to six months before the visa start date
This page set out the guidance received from the French Consulate in London in June 2021. It is more than two year old.
In 2021 we made two inquiries to the French Consulate in London. We first asked whether it was possible to enter France via Spain/Belgium/etc at the start of the visa period. They confirmed that this was possible
We then asked The French Consul the following question,
If my VLS-T start date is for example 01/09/2021 then am I permitted to enter Spain in August and then cross into France on 01/09/2021?
On 14 June 2021, we received the following answer,
You’ll need to have your long stay visa stamped (entry stamp at borders controls)
In your example:
No, you cannot enter France on 01/09 having been in Spain right before as there is no border between Spain and France. Your visa would need to be stamped on or after 01/09 which means that you’ll have to enter Spain in September because in your example, if you enter Spain in August, you’ll get an entry stamp in August so before the beginning of your French long stay visa.
If your enter Spain in August, you’ll have to leave the Schengen area including Spain (so back to the UK as it is not in the EU anymore) in order to enter France or if more suitable, to enter France via Spain on or after 01/09/2021 = your travel date from a non-Schengen country to a Schengen country will have to be on or after 01/09.