The connection can only be made via wi-fi (we never used the SIM), so it doesn't go on the network or roaming. Charging doesn't take long (a couple of hours I'd say) and it's better to keep it plugged in, but it doesn't freeze and hasn't given me any problems whatsoever.
At first you have to do several (compulsory) updates but once you do the last one then it works fine.
You can enter a description of why the collection was made and every day an email is sent from their system with a .pdf with the summary of the collections + description, I don't know the app and we don't use it. Eventually with the online account (to be created on their site, obligatory) you can see the details of the payments and you can set different preferences.
The device is fast and works well with good wi-fi, for small transactions I recommend it.
It's best to ask the customer service or, even better, Sumup(.com) directly. If you collect abroad, you would certainly have to pay the VAT there as well - I doubt whether this is possible with a Swiss contract... LG
1 No
2 Don't know
Sumup's service is disastrous. If the source of income is based on credit cards, better choose something else localised in Switzerland.
You enter everything manually on the device. Everything is nicely listed in the app. At the end of the month, you receive a monthly statement with the exact overview.