13.56 MHz RFID: FCC Part 15.225 and ISED RSS-210 Requirements
13.56 MHz RFID and inductive devices have closely aligned requirements in the United States and Canada. FCC 47 CFR §15.225 and ISED RSS-210 both establish specific field-strength requirements around the 13.56 MHz operating band.
13.56 MHz Frequency Allocation
Both requirements address the frequency region surrounding 13.56 MHz.
| Frequency Range | FCC / ISED Treatment |
| 13.110–13.410 MHz | Lower emission region |
| 13.410–13.553 MHz | Intermediate region |
| 13.553–13.567 MHz | 13.56 MHz operating band |
| 13.567–13.710 MHz | Intermediate region |
| 13.710–14.010 MHz | Upper emission region |
| Outside 13.110–14.010 MHz | General unwanted-emission requirements apply |
The permitted field strength increases substantially within the 13.553–13.567 MHz operating band compared with the surrounding regions.
FCC §15.225 Limits
The FCC specifies the following field-strength limits at 30 m:
| Frequency | Field Strength at 30 m |
| 13.110–13.410 MHz | 106 µV/m |
| 13.410–13.553 MHz | 334 µV/m |
| 13.553–13.567 MHz | 15,848 µV/m |
| 13.567–13.710 MHz | 334 µV/m |
| 13.710–14.010 MHz | 106 µV/m |
This structure is important because a transmitter can have a compliant carrier while still producing excessive emissions immediately outside the operating band.
Frequency Stability
FCC §15.225 requires the carrier frequency to remain within ±0.01% of the operating frequency over the specified temperature and supply-voltage conditions.
For a 13.56 MHz carrier:
±0.01% = ±100 ppm
or approximately:
±1.356 kHz
The FCC temperature requirement is −20°C to +50°C, with the applicable supply-voltage variation also evaluated.
This requirement should be considered during oscillator selection. A nominally accurate oscillator that does not maintain the required stability over temperature may create a compliance issue even when the normal room-temperature measurement is satisfactory.
ISED RSS-210
ISED RSS-210 contains corresponding requirements for 13.56 MHz devices. The current RSS-210 is Issue 11, published June 25, 2024.
RSS-210 should be used together with RSS-Gen, which contains the general requirements applicable to licence-exempt radio apparatus.
For a North American certification program, the applicable issue of both documents should be confirmed before testing.
FCC and ISED: Similar, Not Identical
The technical requirements are sufficiently similar that common test configurations and data can often be used to support both programs.
However, manufacturers should not assume that an FCC test report automatically satisfies ISED requirements.
| Item | United States | Canada |
| Radio requirement | FCC §15.225 | RSS-210 |
| General requirements | Part 15 | RSS-Gen |
| Nominal frequency | 13.56 MHz | 13.56 MHz |
| Operating region | 13.553–13.567 MHz | 13.553–13.567 MHz |
| Field-strength measurement | Required | Required |
| Frequency stability | ±0.01% | Applicable RSS requirements |
| Unwanted emissions | Part 15 requirements | RSS-Gen requirements |
| Equipment authorization | FCC Certification | ISED Certification |
The most efficient approach is normally to develop one representative worst-case configuration that can support both regulatory programs where the measurement requirements permit.
Antenna Design
13.56 MHz RFID equipment is particularly sensitive to antenna configuration.
Important parameters include:
- loop dimensions
- number of turns
- conductor geometry
- matching components
- Q factor
- antenna loading
- enclosure materials
- distance from conductive structures.
Changing the antenna after certification testing can invalidate the assumptions behind the original test configuration.
For this reason, antenna selection should be substantially finalized before formal FCC/ISED testing.
Emissions Outside the Operating Band
The requirements surrounding the operating frequency deserve particular attention.
For example, the FCC permits substantially higher field strength within 13.553–13.567 MHz than in the adjacent regions.
A simplified representation is:
A poorly controlled RF output stage can therefore create problems in the adjacent regions even when the fundamental field strength is within the limit.
RF-Powered RFID Tags
Some RFID systems include tags powered by the reader’s RF field.
The regulatory treatment depends on the specific implementation and whether the tag is designed to operate only in conjunction with an authorized transmitter.
Manufacturers developing an integrated reader/tag system should establish the authorization approach before testing rather than assuming that the tag automatically falls under the reader’s authorization.
Manufacturer Checklist
| Parameter | Confirm Before Testing |
| Nominal frequency | 13.56 MHz |
| Operating band | 13.553–13.567 MHz |
| Frequency tolerance | ±0.01% / applicable ISED requirement |
| Temperature | −20°C to +50°C for FCC stability assessment |
| Supply variation | Applicable FCC/ISED conditions |
| Antenna | Final production configuration |
| RF power | Maximum operating condition |
| Modulation | Worst-case mode |
| Data rate | Worst-case mode |
| Harmonics | Evaluated |
| Spurious emissions | Evaluated |
| External interfaces | Representative configuration |
Summary
FCC §15.225 and ISED RSS-210 provide a practical basis for a common North American compliance strategy for 13.56 MHz RFID products.
The technical overlap is significant, particularly around the 13.56 MHz operating band and field-strength requirements. The programs should nevertheless be treated as separate regulatory submissions, with the applicable FCC and ISED requirements verified independently.
The greatest benefit comes from designing the RF and antenna system around the requirements before the final hardware configuration is locked.