Digikey is actually "funny" here in France - they pretend to have a French website, it shows as the contact their Dutch office (with a Dutch phone number & French fax number - go figure). But when you order from them, everything comes from the US (Digikey doesn't have any EU stock, AFAIK) and while you usually don't pay any customs charges, UPS will send you an invoice for about 20 euro for doing the customs declaration - for every order. Even though filling the customs declaration is the sender's responsiblity and not yours (Digikey apparently couldn't be bothered/doesn't pay for it - so UPS will charge the recipient for it instead!).
However, when you raise a stink, since wtf are these charges about when they weren't mentioned on the original site, they make all the effort to look like an EU company, they have an EU VAT registration and actually do collect the VAT here, they invoice you from Netherlands as well, so as a buyer you have the every right to expect it is a "local" (within EU) transaction (thus you shouldn't have to pay any customs declaration fees) - they will waive the fee! But good luck trying this unless you are a company with a VAT number, they will just tell you to piss off.
I find this a very disgusting business practice.
What's really bizarre is how Digi-Key has different export terms for each country it ships to, seemingly. And it varies by the currency you pay in, too!
For example, here are their export terms for France:
For France, you may select one of the following currencies:
Euro
Free delivery to France on orders of 50,00 € or more.
A delivery charge of 18,00 € will be billed on all orders less than 50,00 €.
Incoterms:
Business-to-Business shipments with a validated VAT number: DDP (Duty and customs paid by Digi-Key)
All other shipments: CPT (Duty, customs, and VAT due at time of delivery)
US Dollar
Free delivery to France on orders of $60,00 USD or more.
A delivery charge of $22,00 USD will be billed on all orders less than $60,00 USD.
Incoterms:
UPS freight pre-paid: DDP (Duty and customs paid by Digi-Key)
FedEx or DHL freight pre-paid: CPT (Duty, customs, and VAT due at time of delivery)
So you'd want to buy in USD and have UPS freight. (Can they even do that for small orders?)
In contrast, here are the terms for Germany (which I would have expected to be identical, given that they're both EU, but they're not!)
For Germany, you may select one of the following currencies:
Euro
Free delivery to Germany on orders of 50,00 € or more.
A delivery charge of 18,00 € will be billed on all orders less than 50,00 €.
Incoterms:
DDP (Duty and customs paid by Digi-Key)
US Dollar
Free delivery to Germany on orders of $60,00 USD or more.
A delivery charge of $22,00 USD will be billed on all orders less than $60,00 USD.
Incoterms:
UPS freight pre-paid: DDP (Duty and customs paid by Digi-Key)
FedEx or DHL freight pre-paid: CPT (Duty, customs, and VAT due at time of delivery)
So you'd definitely want to order in Euros.
And this is the terms for Switzerland:
For Switzerland, you may select one of the following currencies:
Franc
Free delivery to Switzerland on orders of 54.00 CHF or more.
A delivery charge of 20.00 CHF will be billed on all orders less than 54.00 CHF.
Incoterms:
DDP (Duty and customs paid by Digi-Key)
Euro
Free delivery to Switzerland on orders of 50,00 € or more.
A delivery charge of 18,00 € will be billed on all orders less than 50,00 €.
Incoterms:
DDP (Duty and customs paid by Digi-Key)
US Dollar
Free delivery to Switzerland on orders of $60,00 USD or more.
A delivery charge of $22,00 USD will be billed on all orders less than $60,00 USD.
Incoterms:
UPS, FedEx or DHL freight pre-paid: DDP (Duty and customs paid by Digi-Key)
Here, any currency is equal. (For once, living in Switzerland has an advantage for ordering online!) What's not obvious is that UPS or FedEx will still collect Swiss VAT on delivery. (But they don't seem to charge a fee for this.)
Ultimately, any vendor can choose how easy they want to make it for their customers, by providing full-service customs pre-clearance with VAT collection (like AmazonGlobal*), to partial (like Digikey with DDP incoterms), to nothing at all (like Mouser and Farnell).
*Insert rant about Amazon stopping delivery to Switzerland from all Amazon domains except .de, .fr, .it, .es and .co.uk. This really sucks because there are tons of things on Amazon.com and .co.jp that aren't available on the local ones -- and even on the local ones, a HUGE percentage of items do not ship to Switzerland. (Even AmazonBasics stuff is weird: single Lightning cable? No problem. 12-pack? Verboten!) This is because of Switzerland's dumb new VAT law, which somehow Amazon has refused to implement across all its domains, despite it being a simpler VAT algorithm than the old one, which AmazonGlobal supported... Oh, and 2018 came and went without amazon.ch launching as expected.