SDA payment calculations are one of the most misunderstood aspects of running an SDA business. The revenue structure has three distinct components, each with its own source, calculation method, and payment timing. Getting these calculations wrong does not just affect your bottom line, it can lead to over-claiming (a compliance risk), under-claiming (lost revenue), or incorrect owner remittances (a contractual risk).
This guide breaks down each component so you understand exactly where the money comes from and how to calculate it correctly.
Component 1: SDA Funding
SDA Funding is the primary revenue source. It is the payment made by the NDIS to the SDA provider for housing a participant in an SDA-enrolled dwelling.
How it is determined
SDA Funding rates are set by the NDIA and published in the SDA Pricing Arrangements and Price Limits. The amount depends on four factors:
- SDA design category, High Physical Support commands the highest rate, followed by Robust, Fully Accessible, and Improved Liveability
- Building type, apartment, villa/townhouse, house, or group home
- Location, metro, regional, or remote (location loading applies)
- Number of residents, single-occupancy dwellings attract a higher per-participant rate than shared dwellings
Example calculation
A participant living in a single-occupancy High Physical Support apartment in metropolitan Sydney might attract an annual SDA Funding amount of approximately $55,000 to $65,000, depending on the specific pricing period. Divided by 12, that is roughly $4,500 to $5,400 per month.
When it is paid
SDA Funding is claimed monthly through the NDIS payment system. The participant’s NDIS plan must include SDA funding for the claim to be valid. If the plan expires or the SDA line item is removed, the funding stops until a new plan is approved.
Common errors
- Claiming against an expired NDIS plan (the plan end date passed without renewal)
- Using the wrong SDA category rate (e.g., claiming Fully Accessible rates for an Improved Liveability dwelling)
- Not applying the correct occupancy ratio for shared dwellings
Component 2: Reasonable Rent Contribution (RRC)
The Reasonable Rent Contribution is the amount the participant themselves contributes towards their housing costs. It is not NDIS funding, it comes directly from the participant’s income.
How it is calculated
The RRC has two sub-components:
- 25% of the Disability Support Pension (DSP), the DSP rate is set by Services Australia and adjusted in March and September each year. As of 2026, the single-person DSP is approximately $1,116 per fortnight ($2,418/month). 25% of that is approximately $604/month.
- 100% of Commonwealth Rent Assistance (CRA), CRA is an additional payment from Services Australia to help with rental costs. The amount depends on the participant’s rent and circumstances. A single person paying more than a threshold amount in rent might receive approximately $190 to $210 per fortnight ($411 to $455/month).
Example calculation
| RRC component | Fortnightly | Monthly (approx.) |
|---|---|---|
| 25% of DSP ($1,116 × 0.25) | $279.00 | $604.50 |
| 100% of CRA | $195.00 | $422.50 |
| Total RRC | $474.00 | $1,027.00 |
When it is paid
RRC is typically collected monthly from the participant (or their nominee/financial administrator). It is not an NDIS claim, it is a direct rent payment. The collection method and timing should be documented in the participant’s tenancy agreement.
Common errors
- Not updating the RRC when DSP or CRA rates change (twice yearly)
- Collecting more than the allowable amount (over-charging is a compliance risk)
- Not adjusting for participants who receive partial DSP or no CRA
- Failing to account for periods of hospitalisation where the participant may still be liable for RRC
Component 3: SDA Provider Fee
The Provider Fee is the management fee charged by the SDA provider for managing the property on behalf of the owner. This applies when the property is investor-owned (not self-owned by the provider).
How it is calculated
The Provider Fee is typically a percentage of total revenue (SDA Funding + RRC). The exact percentage varies by provider and is set in the management agreement with the property owner. Common ranges are 10 to 20% of gross revenue.
Example calculation
| Revenue line | Monthly amount |
|---|---|
| SDA Funding | $4,800.00 |
| RRC | $1,027.00 |
| Gross revenue | $5,827.00 |
| Less: Provider Fee (15%) | -$874.05 |
| Net to owner | $4,952.95 |
Common errors
- Calculating the fee on SDA Funding only when the agreement specifies gross revenue (including RRC)
- Applying the wrong percentage rate (different owners may have different agreements)
- Not deducting maintenance costs if the agreement specifies net-of-maintenance remittance
Putting it all together: total revenue per participant
Here is a complete worked example for a single participant in a High Physical Support single-occupancy apartment:
| Component | Source | Monthly | Annual |
|---|---|---|---|
| SDA Funding | NDIS | $4,800 | $57,600 |
| RRC (25% DSP) | Participant | $605 | $7,260 |
| RRC (100% CRA) | Participant (via Services Aust.) | $423 | $5,076 |
| Gross revenue | $5,828 | $69,936 | |
| Less: Provider Fee (15%) | -$874 | -$10,490 | |
| Provider retained | $874 | $10,490 | |
| Net to owner | $4,954 | $59,446 |
Why manual calculations are a risk
The risk with manual calculations is not just arithmetic errors (although those are common enough). It is the compounding effect of multiple variables changing at different times:
- DSP and CRA rates change in March and September
- SDA Funding rates are updated annually (sometimes mid-year)
- Participant plans expire and renew on individual schedules
- Provider Fee percentages may vary by property owner
- Occupancy changes when participants move in or out
When these variables are tracked in separate spreadsheets, the probability of a mismatch between what you are claiming, what you are collecting, and what you are remitting to owners increases with every change.
How MySDAmanager automates this
MySDAmanager calculates SDA payments automatically based on the data already in the system:
- SDA Funding is calculated from the participant’s plan, the dwelling’s SDA category, and the current pricing period
- RRC is calculated from the current DSP and CRA rates, updated when rates change
- Provider Fee is calculated from the percentage set in the owner’s management agreement
- Variance detection flags any payment that differs from the expected amount by more than $500
- Xero sync pushes the calculated amounts directly to your accounting software
- Owner Folio Summaries are generated with one click, showing per-participant revenue breakdowns
The system does not replace your financial judgement. It ensures the arithmetic is correct, the rates are current, and the calculations are auditable.
Key takeaways
- SDA revenue has three components: SDA Funding (NDIS), RRC (participant), and Provider Fee (retained by manager)
- Rates change multiple times per year: DSP/CRA in March and September, SDA Funding annually
- Manual calculations compound errors: Multiple variables changing on different schedules create drift
- Over-claiming is a compliance risk: NDIS can claw back incorrect claims and investigate systemic over-charging
- Under-claiming is lost revenue: Many providers leave money on the table by using outdated rates or missing CRA entitlements
Whether you automate these calculations or continue doing them manually, the important thing is to understand the structure. Every dollar of SDA revenue traces back to one of these three sources, and getting the calculation right protects both your compliance standing and your bottom line.