The Submitting Firm, which is displayed at the bottom of the Create Dealing screen, is chosen by default by Landonline based on who would generally submit in a routine transaction.
The Submitting Firm can be changed by any party to the dealing prior to any instrument being released. Only the named Submitting Firm can change it after release.
When a transfer is included in an e-dealing, the firm acting for the transferee will be the Default Submitting Firm.
If there's more than one transfer in the same dealing, Landonline will show the transferee for the FIRST transfer as the Default Submitting Firm. This generally won't be appropriate in a same day back-to-back settlement where it would be the transferee in the last transfer being the submitting party.
In summary, you should always check the Submitting Firm in a back-to-back settlement in the same dealing and change as appropriate. The same also applies where a mortgagee is separately represented and wishes to be in control of submitting.