In Odoo 18, payment creation is optional and payments no longer create journal entries. Payments only need to be created if you wish to record additional details about the expected transaction or are sending payments via bank transfer integration such as ACH, BACS, ISO20022, SEPA, etc.

Internal Transfers can be handled during bank reconcilation by clicking Internal Transfers on both the sending and receiving Bank Journals, and this process is the same whether you created an outgoing (Vendor) and incoming (Customer) payment for the two sides Internal Transfer or did not create either.

Outbound (withdrawal):

Inbound (deposit):

Note: If the inbound payment to the receiving bank is in a different currency (you will initially see that the debit  and credit amounts are not the same as the withdrawal) ...

... switch to List View and enter the Foreign Currency and Amount Currency to update the exchange rate that Odoo uses:

Customers who want the prior behavior where journal entries were created need to create outstanding accounts and configure their bank journals to use them. This is done by adding these accounts to each relevant Payment Method on the Incoming Payments and Outgoing Payments tabs on the Journal.

In this case you would create a Manual Journal Entry using the outstanding accounts. Enter either the known or estimated amount for the secondary currency:

Then match with the Journal Entry during bank reconcilation:

Outbound (withdrawal):

Inbound (deposit):

If you estimated the amount of foreign currency, Odoo will add a gain/loss adjustment to account for the difference.

Note: You may see an adjustment entry added when one is not needed (if you pre-purchased at a specific exchange rate and updated the statement line as explained in the first scenario). If this happens, simply delete it and match against the journal entry as shown.