You can register the caveat on title but it may be a breach of the mortgage as the Mortgagee has to be notified.
It has to be drafted carefully to set out the verbal agreement.
I cannot draft the caveat only provide you with the form to complete.
Here is some information followed by the form
You set out that the loans are paid out of the respective shares.
I hope this makes sense and is of assistance. If there is nothing further
thank you for using my services.
If I have missed anything, or you have any further questions please let me know
If there is anything else in the future please do not hesitate to ask.
Please do not forget to leave positive feedback.