Hello Fratonprop

Thanks for posting on the Community. 

You can create an account for this within your chart of accounts to post the past transactions to. To create a new account:

1. Go to Settings ⚙ and select Chart of Accounts.
2. Select New to create a new account.
3. In the Account Type ▼ dropdown, choose an account type (for bank accounts,  select Cash at bank and in hand).
4. In the Detail Type ▼ dropdown, select the detail type that best fits the transactions you want to track (click here to learn more about detail types).
5. Give your new account a name and add a description.
6. When you're done, select Save and Close.

You can now select this account when recording the transactions manually, or upload a CSV containing the transactions if you're able to download a file from your bank.