Sumup transactions

I'd like to join you here and offer help with your banking concerns, The Dinky Drinky.

It's possible that SumUp isn't added as participating financial institution yet. This is why you can't see it when trying to sync the account. 

As a workaround, you can ask for a CSV copy of your transactions from them and import it in QBO. I'd be glad to share all the steps with you. 

First, make sure to use either a 3-column or 4-column format of your CSV file. This is to make sure that it will be compatible and will be imported successfully.

Here's an article that adds more details about this: Format CSV Files in Excel to Get Bank Transactions into QuickBooks.

Second, follow these steps on how to import the SumUp transactions into your account: 

1. Go to the Banking or Transactions menu and go straight to the Banking tab.
2. Select Upload transactions and choose Select files.
3. Look for the CSV file and choose Open.
4. Click Continue and look for the savings account that you created.
5. Choose Continue and select a format.
6. Follow the next prompts to import the file.

Additional details are also shared in this article: Manually Upload Transactions Into QuickBooks Online.

In the meantime, you can request for SumUp to be added to the list of participating banks for online banking. Here's how:

1. Go back to the Banking menu.
2. Select Connect account.
3. Search for the name of your bank or financial institution. Once QuickBooks is unable to find your bank, you will get the message, "Hmm, we can’t find [name of the bank you entered] in our list of supported banks," and you will be presented with helpful tips to try and locate your bank account.
4. Click Select Request.
5. Enter your bank's name and web address (URL) in the field provided, then select Request. 

Let me know if you're able to add your transactions in QuickBooks. The Community is always here if you need anything else.