Mortgage aggregation costs

Commission split vs flat-fee aggregation

The way an aggregator charges for its services can have a significant effect on the economics of a mortgage broking business.

Last reviewed: October 2026

Two common approaches are a commission-split model, where the aggregator retains an agreed percentage of commission, and a flat-fee model, where the broker pays a fixed periodic fee and may retain 100% of the commissions received through the aggregator.

Neither structure is automatically right for every broker.

The important question is not simply which model has the lowest headline price. A broker should understand the total cost of aggregation, what is included for that cost, how the arrangement changes as the business grows, and the ownership and exit terms attached to the agreement.

The short answer

Under a commission-split model, the cost of aggregation generally rises as the broker earns more commission.

Under a flat-fee model, the core aggregation cost can remain relatively stable as settlement volumes and commissions increase, although additional fees may still apply.

For an established broker writing consistent volumes, this difference can become material over time.

For a newer or lower-volume broker, however, a commission split may initially involve a lower fixed cash commitment.

The appropriate model therefore depends on the broker’s production, business stage, support requirements and the complete terms of the aggregation agreement.

What is a commission-split aggregation model?

Under a commission-split model, the aggregator retains an agreed percentage of the commission generated by the broker and passes the remaining percentage to the broker.

For example, if a broker is on an 85/15 arrangement, the broker retains 85% and 15% is retained under the aggregation arrangement, subject to the precise terms of the agreement.

The percentage may apply to:

upfront commission;
trail commission;
or both.

Some arrangements may also include additional fixed or transaction-based fees.

The important point is that the dollar cost of the percentage generally increases as the broker’s commission income increases.

What is a flat-fee aggregation model?

Under a flat-fee model, the broker pays an agreed periodic fee for aggregation services rather than giving up a percentage of every commission received.

Depending on the particular agreement, the broker may retain 100% of upfront and trail commissions while paying a monthly or other periodic aggregation fee.

There may still be separate costs for technology, licensing, compliance, software, administration or optional services, so brokers should compare the complete cost rather than the headline monthly figure alone.

For a productive broker, a fixed-fee structure can make the cost of aggregation more predictable as the business grows.

Why the difference becomes more important as a broker grows

A percentage-based cost grows with the income to which that percentage applies.

If a broker’s commission income doubles and the commission split remains unchanged, the dollar amount retained under that percentage arrangement will generally increase accordingly.

A genuinely fixed aggregation fee behaves differently. If the fee remains unchanged while the broker’s production rises, the aggregation cost represents a progressively smaller percentage of the broker’s gross commission income.

That distinction is one reason experienced brokers should periodically review the economics of their aggregation arrangement rather than assuming that an agreement that suited them earlier in their career is still appropriate today.

A simple example

Consider a broker whose gross upfront and trail commissions total $100,000 in a year.

On a 15% commission-split arrangement, $15,000 represents the commission share retained under that split before considering any other applicable fees.

If gross commissions increased to $200,000 and the same 15% split applied, that amount would increase to $30,000.

Gross commissions $100,000 × 15% split: $15,000
Gross commissions $200,000 × 15% split: $30,000

A flat-fee arrangement works differently because its core fee is not calculated as a percentage of commission.

The comparison therefore becomes increasingly important as commission income grows.

This example is illustrative only. Actual aggregator agreements, commission arrangements, fees, services and taxation treatment vary.

Upfront commission and trail commission should both be considered

A broker should not assess an aggregation arrangement using upfront commission alone.

Mortgage broker remuneration commonly includes both upfront commission following settlement and ongoing trail commission based on the outstanding loan balance.

Trail can become an increasingly valuable business asset as a broker builds a larger loan book.

Where an aggregation agreement retains a percentage of trail as well as upfront commission, the cumulative cost can therefore increase as the broker’s book grows.

When comparing models, determine exactly what percentage, if any, applies to:

upfront commission;
trail commission;
bonuses or other lender payments;
commercial or asset finance income;
referral income where relevant; and
any future income generated from the loan book.

The calculation brokers should make

The simplest starting point is to calculate the actual annual dollar cost of the current aggregation arrangement.

For a commission-split model

Annual aggregation cost from the split =

gross commissions × aggregator percentage

Then add any other compulsory fees.

For a flat-fee model

Annual core aggregation cost =

periodic aggregation fee × number of periods

Then add any other compulsory fees.

The comparison should be made using realistic commission income rather than settlement volume alone.

Estimate your aggregation cost

Use the Morbanx Aggregation Calculator to estimate what a commission split or flat monthly aggregation fee could mean for your business.

Use the aggregation calculator

The break-even point

A useful measure is the point at which the annual cost of a commission split becomes equal to the annual cost of a fixed-fee arrangement.

For example, if a fixed aggregation arrangement costs $12,000 per year and the alternative arrangement retains 15% of gross commission, the mathematical break-even point would be $80,000 of gross annual commission before considering any additional fees or differences in services.

Fixed arrangement per year: $12,000
Commission split: 15%
Break-even gross annual commission ($12,000 ÷ 15%): $80,000

Above that level, the percentage cost would exceed $12,000.

Below that level, the percentage cost would be less than $12,000.

This calculation does not determine which aggregator is better. It simply identifies the economic break-even point between two fee structures.

Figures are illustrative only and do not represent Morbanx Aggregation pricing.

Cost is only one part of the comparison

Aggregation should not be selected solely on price.

The MFAA’s guidance for brokers considering an aggregator highlights a much broader range of issues, including fees, lender access, licensing, compliance support, technology, professional development and business support.

A lower-cost arrangement may provide less of something a particular broker values.

Conversely, an expensive arrangement does not necessarily provide better support.

A broker should compare both the economic model and the services received for that cost.

What else should a broker compare?

Before deciding between aggregation models, consider:

ownership of clients;
ownership and portability of the trail book;
what happens to trail if the broker leaves;
lender panel breadth and relevance;
lender accreditation support;
credit licence arrangements;
compliance support;
file-review requirements;
technology and CRM platforms;
commission processing;
training and professional development;
access to experienced support;
business guidance;
community and peer support;
additional software or administration charges;
minimum-volume requirements;
joining or exit fees;
notice periods;
restraint or non-solicitation provisions; and
any conditions attached to transferring the loan book.

For a broader comparison, read:

How to choose the best mortgage aggregator in Australia

Commission split: potential advantages

Depending on the particular arrangement, potential advantages can include:

lower fixed costs when commission income is low;
cost moving broadly in line with income;
potentially easier cash flow for a broker in the early stages of building a business; and
access to services without committing to a higher fixed monthly cost.

Potential disadvantages

Depending on the agreement:

the dollar cost increases as commission income increases;
a percentage may continue to be deducted from trail;
the long-term cumulative cost can become substantial for productive brokers; and
the broker may continue paying a higher dollar amount without receiving additional services as production grows.

Flat fee: potential advantages

Depending on the particular arrangement, potential advantages can include:

predictable core aggregation costs;
the ability to retain a greater proportion, or potentially 100%, of commissions;
improved operating leverage as production increases; and
easier visibility of the direct cost of aggregation.

Potential disadvantages

Depending on the agreement:

the fixed fee is payable even during lower-volume periods;
it may initially cost more than a percentage arrangement for a very low-volume broker;
additional technology or service charges may still apply; and
the value depends heavily on the quality of support and services included.

What about a broker who already has a large trail book?

For an established broker, trail ownership and trail treatment deserve particular attention.

A mature trail book may represent years of client relationships and settled lending.

The broker should establish:

whether any aggregation percentage applies to existing or future trail;
who legally or contractually owns the trail rights;
whether the trail can move if the broker changes aggregator;
what happens to trail following resignation or termination;
whether there are purchase, transfer or release conditions; and
whether any ongoing fee continues after departure.

These issues should be understood from the actual aggregation agreement rather than assumed from marketing material.

Understand client and trail ownership

When might a commission split make sense?

A commission-split structure may suit a broker who:

is at an early stage of building commission income;
wants to minimise fixed monthly commitments;
receives services that justify the percentage being retained; or
has deliberately chosen a variable-cost business model.

The decision should still be reviewed as production increases.

When might a flat-fee model make sense?

A flat-fee structure may be attractive to an established or growing broker who:

is writing consistent volumes;
wants greater certainty around aggregation costs;
wants to retain 100% of commissions where the arrangement permits;
values ownership and control of the business;
expects production to increase; and
wants the financial benefit of that growth to remain primarily within the broking business.

The fee structure should still be considered alongside service, compliance, technology, lender access and agreement terms.

Where Morbanx Aggregation fits

Morbanx Aggregation is designed primarily for experienced independent mortgage brokers who want to operate their own business while having direct access to experienced aggregation support.

The Morbanx model is built around brokers retaining 100% of their commissions rather than giving up a percentage of commission as production increases.

The model also places emphasis on ownership of clients and trail, practical broker support, business guidance, professional development, compliance support, community and access to the infrastructure and lender panel available through Specialist Finance Group.

Morbanx is not positioned as the right aggregation solution for every broker.

The objective is to provide an alternative for brokers whose business model and priorities align with this structure.

Why Morbanx How the support model works

Thinking about changing aggregator?

The economics may be one reason to review an aggregation relationship, but changing aggregator involves more than comparing fees.

Lender accreditations, licensing arrangements, technology, client records, pipeline management, trail arrangements and the timing of the transition all need to be considered.

What to consider when switching aggregators Aggregator transition checklist

Frequently asked questions

What is a commission split in mortgage aggregation?

A commission split is an arrangement where an aggregator retains an agreed percentage of commission generated through the broker’s business and passes the balance to the broker. The percentage may apply to upfront commission, trail commission or both, depending on the agreement.

What is flat-fee mortgage aggregation?

Flat-fee aggregation generally involves the broker paying an agreed periodic fee for aggregation services rather than giving up a percentage of commission. Depending on the agreement, the broker may retain 100% of upfront and trail commissions while paying the fixed aggregation fee and any applicable additional charges.

Is a flat-fee aggregator always cheaper?

No. The result depends on the broker’s commission income, the amount of the fixed fee, any additional charges and the services included. A commission split may cost less for a low-volume broker, while a flat-fee arrangement can become more economical as commission income increases.

How do I compare a commission split with a monthly aggregation fee?

Convert both arrangements to an annual dollar cost. For a commission split, multiply gross commission by the percentage retained and add other compulsory fees. For a flat-fee model, annualise the periodic fee and add other compulsory charges. The Morbanx Aggregation Calculator can help estimate the difference.

Should I include trail commission in the calculation?

Yes. If the aggregation agreement applies a percentage or fee to trail commission, it should be included when calculating the total cost. Trail can become increasingly important as a broker’s loan book grows.

Does paying a flat fee mean I automatically own my trail book?

No. Fee structure and trail ownership are separate issues. Ownership, portability and treatment of trail should be confirmed from the aggregation agreement.

What other aggregator fees should I look for?

Depending on the aggregator, other costs may include joining fees, monthly administration or service fees, compliance costs, software charges, licensing-related costs, marketing fees and other service charges. Brokers should obtain a complete breakdown before comparing arrangements.

Is the cheapest aggregator the best aggregator?

Not necessarily. Cost is important, but so are lender access, compliance support, technology, business support, professional development, service quality, ownership terms and exit conditions.

Can an experienced broker save money by moving from a commission split to a flat fee?

Potentially. The result depends on current commission income, the percentage being retained, the alternative fixed costs and other fees. Established brokers with higher commission income may find that the dollar cost of a percentage arrangement has become significant, but the complete aggregation offering should be compared before making a decision.

Does Morbanx Aggregation take a percentage of broker commissions?

Morbanx Aggregation’s core model is structured so brokers retain 100% of their commissions rather than paying Morbanx a percentage of commission. Brokers should discuss the complete commercial arrangement and services with Morbanx before making an aggregation decision.

Next step

Understand what your current aggregation model may be costing

If you are reviewing your aggregation arrangement, start by understanding the numbers and then consider the support, ownership, technology and agreement terms around them.

Use the aggregation calculator

Call Andrew directly: 0417 512 306

Prefer to speak with Mia, our AI assistant: 0468 009 746

Private · Practical · No obligation

This information is general in nature and is provided for educational purposes only. Aggregator agreements, commission arrangements, fees and services vary. Brokers should review the relevant agreement and obtain appropriate professional advice before making business, legal, financial or taxation decisions.