I used Wise for large amounts from US. Worked great. Then converted to CHFs within my Wise account, then transferred CHFs to my local bank.

If I had simply had USDs transferred from a US bank to my local bank, I would have had to open a USD account here, then anytime I needed to convert them to CHFs the bank (UBS in this case) would have taken 2% fee off every conversion. Wise, conversion is far cheaper and exchange rate better than bricks and mortar banks gives, plus you are in control of when you want to convert.

Not only that but the rate they charge is often 5-6% worse than the interbank rate you get with Wise/Revolut. Paypal is the same - never ever let Paypal do a currency conversion for you.

Hey! Sorry to jump in, but that's exactly what I'm planning on doing. Do you get charged as an international transfer or, being IB a UK based entity, it's considered a same-country transfer?

Thank you for your advice everyone! (I don't seem to have a 'Thanks' button to thank posters individually).

Looks like (Transfer)Wise is my best option! I'll just have to get someone to double-check the account details that I enter...

Hey for 20% I’d be happy to.

Ha, I know I said I was bad at this stuff, but even I wouldn't go for that deal!

15%?

No worries it’s actually quite easy. Don’t worry, just double check your figures.

Thanks, I will (and triple and quadruple...)

I got it free on both sides. IIRC, you get at least one free transfer per month per country.

Have you considered buying seliing a Bitcoin to make a conversion ?

Don’t.

Lame answer.

Stupid suggestion, in context.

It's clearly not if one understands what FX conversion is underneath. But hey, your one folded brain couldn't comprehend it, it happens.

I would be interested if anyone has concrete numbers of different providers for large amounts like 100k chf or even much more. Which platform provides the lowest bid ask for retail customers

Revolut

For these sums I recommend Interactive Brokers as Phil_MCR already mentioned. You can buy/ sell at the interbank rate or submit an order at a rate of your choosing. All for a USD 2 fee.

That's great news, thanks! To reply to the OP, I think Interactive Brokers is probably the best solution if you're also into investing.
Otherwise a Revolut account might be easier to open

is there any withdrawal limitation with Interactive Broker towards Swiss banks?

I might have read that Neon did not allow to transfer money to it?

What you need is a specialist currency trader who can offer you a couple of options. Speak to someone like https://www.smartcurrencyexchange.com/, there are lots of them in UK.

You can either lock in a specific market rate now for a future transaction or do a spot trade. I think all transactions About 3K are free and you get the actual MM Rate.

I would speak to one of the traders to get an idea of rates they think they can achieve.