The restrictions came into force yesterday and require banks to keep their low-deposit lending to no more than 10% of their new loans.
Banking Ombudsman Deborah Battell said mortgage complaints were already the highest single category of complaints.
Her office has created two new guides to help customers. They can be found here.
"We don't know how many people will be affected by the LVR restrictions as each customer's situation will be different. However, the guides are designed to help customers avoid problems with new mortgage lending. If customers do have problems we suggest they first contact their bank to try and resolve their individual situation. If they are still unhappy with what the bank proposes, they can contact the Banking Ombudsman scheme."
She said the bank could not investigate commercial judgements by the bank but could look at administrative errors in the lending application process.
