Using IBKR, is there no way to roll a credit spread from 2 contracts to 3 contracts? I.e July 28th - 2 contracts to August 2nd - 3 contracts? The only way I see is to roll the current quantity and then buy a 3rd contract/spread seperately.

@H2OCan

This query does not depend on the brokerhouse, instead it depends on what YOU onw or what you do not own. If you own contracts for two "Credit-Spreads", then you can only roll those contracts and nothing else. So IBKR is acting according to given rules.

You may are interested to read the following to bring some more insight knowledge to this topic: https://www.investopedia.com/terms/o/order-book.asp

Symple