You'll have to create a service item for the commission deducted by Yoco. Then, apply it to the sales transaction you'll create in your QuickBooks Online (QBO) account, @Jen72. This way, you'll able to match them to the downloaded bank transactions and reconcile your account accordingly.

In your QBO account, all the information entered should be based on your real-life transactions. Before reconciling your account, let's first make sure the transactions entered in QBO is match with your bank statement. To do this, you need to create a service item for the commission deducted by Yoco. Here's how:

1. Go to the Gear icon.
2. Select Product and Services.
3. Click the New button.
4. Choose Services from the Product/Service information window.
5. In the Name field, enter any name you want (i.e. Yoco Commission).
6. Put a check-mark in the I sell this product/service to my customers box.
7. In the Income account field, select the Expense account.
8. Select the Save and close button.

I've attached a screenshot that shows the fifth to eight steps.

After that, you'll have to create a sales transaction and apply the service item with a negative amount. This way, the commission will be deducted from the sales price. You can refer to the screenshot below for your reference.

Then, go to the For Review tab in the Banking menu to match the transactions. For the detailed steps, you can check out this article's Match an existing transaction section: Categorise and match online bank transactions in QuickBooks Online.

Once done, you should be able to reconcile your accounts smoothly. With this, I'd recommend performing the process every month. This way, you can early detect errors and monitor the growth of your business. Kindly refer to this article for a step-by-step guide: Reconcile an account in QuickBooks Online. 

Additionally, you can pull up any transaction and reconciliation reports to make sure you've entered everything correctly. Just go to the Reports menu, then select the report you want.

Please let me know if you have other concerns. I'm just around to help. Take care always.