The cheapest bond in South Africa is rarely found by picking a brand; it is won by putting the same application in front of several lenders at once.
A bond originator such as ooba Home Loans, BetterBond or MortgageMax takes one set of documents and submits it to multiple banks simultaneously. You pay nothing for this, because the originator is paid a commission by whichever lender ultimately registers the bond. The benefit is not only convenience. A decline from one bank stops being the end of the road when three others are reading the same file, and the offers that come back give you a documented basis to negotiate. Banks hold real discretion over the margin they quote above or below prime, and a competing written offer is the thing that unlocks it.
Applying to several lenders inside a short window also limits the damage to your credit record, because bureaus recognise a cluster of enquiries for the same purpose as one shopping exercise rather than a borrowing spree. Compare what comes back on identical terms: the same loan amount, the same repayment period and the same rate type. Then add the once-off initiation fee, which is capped under the National Credit Act at roughly R6 000 including VAT on a bond, and the monthly service fee of up to R69, before you decide which offer is actually the cheapest.
And remember that the decision is not permanent. If your credit profile improves or the market moves, you can switch your bond to another lender later, weighing the new rate against the registration costs of moving.