Posted in 2014 here.
Not so fast. To for instance Sweden from non-EU, it’s not about ATC at all. It’s customs. The Swedish admin obviously distribute to the customs as well. The (customs) rules say one hour before departure. The Norwegian ATC does not forward anything to customs, you have to do it yourself (but you can hook it off if filing from IPPC). The same rule apply though. One our before departure. If flying to a non international airport, it’s 4 hours before crossing the border.
Responding would take this even more off topic, so I won’t, otherwise I would need to start a new thread 
More reading can be found with a search.
I am not aware of any new concessions on the earlier-posted rules for not having to file a FP. And we have so many people here from CZ DE CH etc that somebody will post if there is something.
Peter wrote
In reality there is no 1hr notice IME.
Some AROs enforce the 60 minute limit. (E.g. the Swedish ARO does,) Of course if you don’t file with an ARO you can file as late as you wish as long as there is time for the FPL to be distributed.
As soon as the departure tower has the flight plan, which will be seconds after it has been injected into the AFTN, you can fly. This is also true for IFR which “in theory” needs 3hrs.
In theory it is 60 minutes, Three hours is not a filing limit but the time when slots are allocated, If you file later you may get a worse slot that you would have otherwise.
If VFR, you have to ask yourself: who checks for a duplicate FP? In IFR, it is IFPS (Eurocontrol). In VFR, I am not aware of any mechanism.
There is no database, other than national-security databases around the place. These could be used to do a duplicate check within a given country.
This sort of thing came up here.
But it seems clear than once a FP has been closed (ARR message) you or anybody else can file a new FP. Whether you are airborne at the time is irrelevant 
But to get back to the topic, other than what ji describes, I don’t see this is a fish worth frying, given the many limitations on this concession (starting with “no CAS”). And if you get it wrong, you could get busted. There have been various busts, IIRC involving border crossings Italy / Switzerland and especially involving some accident. Maybe this one.
@Peter in reality it is, yes. I have that in France where they do not let me file anything sooner than 1 hour in the future.in particular a topic for an unplanned stop, that can happen any time when flying VFR or with a crowded cabin.
Last time I filed the following flight plan during descent. But it’s a bit tricking the system. You have to close the active flight plan first, while flying, if not the system rejects the second plan.
And all of that while one should be doing approach briefing, traffic avoidance, airspace circumnavigation. So I really don’t encourage nobody to do that 😉
In reality there is no 1hr notice IME.
As soon as the departure tower has the flight plan, which will be seconds after it has been injected into the AFTN, you can fly. This is also true for IFR which “in theory” needs 3hrs.
Activation, if needed, can be a problem, yes.
Thanks. I just wanted to know where to find the official source, so I could check it to see if anything had changed from these old posts. But it seems the official source is behind a paywall, in German only, and a different paywall than what is included in the VFR AIP Germany subscription.
I agree that filing a flight plan is generally not a hassle, I use skydemon and it is super simple. However, it is the one hour notice that bothers me, as it is one more thing to worry about and manage as plans change.
Using a flight plan is more cumbersome than filing one, especially when one flys to airports that can’t activate a flight plan, and are right next to a border. I take off, leave the circuit, switch to FIS, circle, wait for confirmation of activation, and then cross the border and switch to the next FIS.
This thread should have the info further back (66 posts so far; check especially the first 20) but there are so many gotchas on this concession that I would not bother.
Filing a flight plan is trivial nowadays. This has to be VFR and for that any FP filing service will do, since there is no route to validate. I just use eurofpl.eu for these.
