An average runoff rate for an Australian trail book needs a consistent measure of annual balance loss. RBA, APRA and ABS publications provide useful context, but their measures do not establish a directly comparable national broker-book average. Use your own annual balance runoff as the starting point, then compare books with similar loans and measurement rules.
The Average Runoff Rate for an Australian Trail Book
There is no defensible annual broker-book runoff range to quote from these official series alone. A refinancing figure covers only part of the balance leaving existing loans. A total runoff measure must also capture scheduled principal repayments, extra repayments and discharges following property sales.
The comparison must follow the loans already in the book. New settlements can replace lost balances and make the whole book grow while its existing loans run off. Report those two movements separately when you assess retention or prepare a book for sale.
Use a rolling 12-month result for your book as a working benchmark. For an external comparison, ask for the same balance definition, loan population and reporting period. A percentage without those details cannot tell you whether your book retains balances better.
Where the Benchmark Comes From
The official sources describe different parts of the mortgage market, so combining their headline figures does not produce a broker-book runoff average.
| Official Source | What It Measures | How It Helps the Comparison |
|---|---|---|
| ABS Lending Indicators | New borrower-accepted loan commitments, including internal and external refinancing | Shows refinancing activity, with external refinancing separated from lending for property purchases |
| APRA Property Exposures | Residential mortgages outstanding and new mortgage approvals for authorised deposit-taking institutions | Provides context for the size and composition of bank mortgage lending |
| RBA Securitisation Dataset Analysis | Individual loans in securitisation pools, including borrower repayments and buffers | Explains repayment behaviour and differences between the sample and the wider market |
The ABS Lending Indicators release for 2026 measures commitments. A commitment is not a matched record of the old balance leaving a broker’s book. A client can also refinance through you and remain your client after their old loan closes.
APRA’s quarterly statistics cover authorised deposit-taking institutions, including banks. Their outstanding balances do not isolate a fixed group of broker-originated loans. Changes in those balances also include new lending.
The RBA’s Securitisation Dataset explanation describes loans backing residential mortgage securities. Loan selection and revolving pools affect its composition. The dataset tracks loans rather than borrowers across a refinance, which limits its use for measuring client retention.
A securitised pool’s prepayment rate measures early principal repayments under that pool’s definition. It can include full repayment through refinancing as well as partial extra repayments. Check whether scheduled principal is excluded before comparing it with total balance runoff.
Prepayment buffers are a different measure again. The RBA’s 2026 household resilience analysis discusses savings available against future repayments. A buffer measured in months of repayments is not an annual percentage of balances lost.
A comparable annual rate needs the opening balances of a fixed loan group and its remaining balances after 12 months. The calculation is 100 × (opening balance - remaining balance) ÷ opening balance, excluding new lending. Reconcile redraws and top-ups separately. A national estimate would need these matched balances across a representative group of broker books.
Why Broker Books Run Off Faster or Slower
Loan mix and borrower behaviour can move two books’ runoff rates apart even when their brokers provide the same service. Compare similar groups before treating a difference as a retention problem.
- The rate cycle changes the savings available from refinancing and the pressure on household repayments. A rate change can prompt a review without producing a discharge.
- Loan age changes the repayment profile. Older principal-and-interest loans repay a different share of their remaining balance than newly settled loans.
- Fixed-rate expiries create review points. A book with many loans leaving fixed rates together can have a concentrated period of refinancing.
- Investor share changes the mix of repayment types and property decisions. Separate interest-only loans from principal-and-interest loans before interpreting the difference.
- Cashback competition changes the incentive to switch lenders. Count the resulting loan discharge separately from whether the client stays with your brokerage.
- Client review frequency affects when you learn about a pricing or service problem. Track reviewed clients separately to assess whether your retention work changes outcomes.
These drivers explain what to investigate. They do not establish a numerical adjustment you can add to a national average.
How to Compare Your Own Book
Compare annual balance runoff over the same period, excluding new lending and using the same loan group. Start with the runoff calculation guide for the monthly calculation and reconciliation steps.
When a constant monthly runoff rate is expressed as a decimal, its annualised equivalent is 1 - (1 - monthly rate)^12. In a hypothetical example, 1% each month becomes 1 - 0.99^12, or about 11.36% a year. Multiplying by 12 gives 12%, which ignores the shrinking balance.
Annualising one month assumes that month’s rate repeats. For an observed annual result, use the actual opening and closing balances of the same loan group. A one-off large discharge makes a single month’s annualised figure a poor guide to the next year.
Keep gross balance and the balance used to pay trail separate if offset treatment differs. Also separate reporting gaps from genuine repayments. The guide to missing trail commission explains how a payment gap can distort the apparent loss.
Balance Runoff vs Client Attrition
Balance runoff weights each dollar lost, while client attrition counts clients who leave. Loan attrition counts closed loans, so it can rise when a retained client refinances through your brokerage.
Consider a hypothetical book with 100 clients and $50 million in opening loan balances. Five clients leave, taking $5 million of loans with them. Client attrition is 5%, while the balance lost through those departures is 10% before repayments on retained loans.
The same five departures could remove much less balance in a book where those clients have smaller loans. Scheduled repayments can also reduce balances while every client stays. Report client attrition alongside balance runoff when you explain the cause of a change.
What Your Runoff Rate Tells You
A rate above a comparable benchmark means existing balances are shrinking faster under that shared definition. With an unchanged commission basis, less eligible balance means less trail. Investigate the loans responsible before changing your retention approach.
If large clients leave, review the reasons for their departures and the timing of earlier contact. If existing clients refinance through you, record their retained relationship and replacement lending separately. Use the retention process for mortgage brokers to turn those findings into a review process.
A rate below a comparable benchmark means balances are lasting longer. Check whether that result comes from retained clients, interest-only lending or a younger loan mix. Use the evidence when forecasting income, while allowing for future repayments and discharges.
Faster runoff also reduces the future trail available to a buyer, all else equal. Slower runoff supports a longer income stream, but does not determine the sale multiple by itself. The guide to valuing a mortgage broking business explains the other factors.
When an external benchmark lacks a matching definition, compare your book with its own earlier periods. Keep the method unchanged so the movement has a clear meaning.
Track Your Runoff Against the Benchmark
Track My Trail’s Performance Dashboard charts trail runoff and loan book runoff month by month, alongside the monthly loan book. Use those trends to compare income loss with balance loss. Trail History stores your uploaded reports, and Historical Analysis compares stored periods without uploading them again.
Review the comparison quarterly and after rate changes. Record the comparison’s definition beside your result, including whether clients who refinance through you remain counted as retained. Investigate a change in the largest loan groups before using the rate in a valuation or income forecast.
