Europe - International Connection Time is ZRH

I have a flight from FCO to LHR with a connection in ZRH. I will be flying exclusively on SWISS. Will I need to clear customs in ZRH? How much time will I need to clear customs if necessary?

You will go through immigration in Zurich to exit the Schengen area, but no further security. You go through customs (and immigration) at LHR.

How much time should I need for the connection?

I believe the OP will find faster help in the Europe destination forum. Please follow the discussion there. :)

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essxjay
TS/S moderator

How much time should I need for the connection?

The airport or airline web site should tell you what the minimum connecting time is. It will probably be in the region of one hour.

If you have been sold this as a single ticket it will be plenty of time.

Generally, I'd expect the process to take minutes at most.

Plus any queue time due to peak travel load, but despite flying from ZRH at various times, I've never seen much of a queue.

at calm times, I've been able to do so in 7 minutes, which was with a toilet break included last time.
Anyway, your flight from FCO will arrive at the A-gates (Schengen) and you will need to transfer to the B-gates (non-Schengen) for your LHR flight.