Update: TP-Link published firmware 1.4.1 (build 260721) for the U.S. Kasa KP125M hardware V1/V1.6 on August 3, 2026. The notes add Matter 1.3 energy reporting, a consumption-data correction, Charge Guard, and security/stability improvements. Reviewed September 27, 2026. This is a documentation-based update, not a claim that WesternTechy has independently tested every controller or plug revision.
The most useful part of this update is easy to misunderstand. An energy-monitoring plug has long been able to show usage inside its maker’s app, but that doesn’t mean a third-party Matter app can see the same figures. TP-Link’s KP125M release notes now say Matter 1.3 can expose real-time and historical energy information to compatible apps. The other half of the equation is your receiving platform: the manufacturer expressly warns that support is inconsistent. A successful on/off command alone still does not establish that your controller can display or automate from energy data.
What changed in firmware 1.4.1?
The official KP125M V1 and V1.6 pages list the same August 3 release for the U.S. model. A product-family name is not a promise that every regional or unrelated Kasa plug receives that firmware. Match the label, hardware version, firmware version and regional support page before applying these notes to your device.
| Release-note item | What it means for an owner | Limit to keep in mind |
|---|---|---|
| Matter 1.3 energy reporting | Compatible Matter apps can receive power and energy data, including historical information where supported. | Your controller/app must actually implement the function; switching support alone is not enough. |
| Consumption-data correction | TP-Link says it fixed abnormally high power-consumption data in certain scenarios. | That is a vendor fix description, not a guarantee that every measurement or old reading is accurate. |
| Charge Guard | A setting is added under Device Settings in the manufacturer’s app. | Confirm exactly what the setting does for your hardware; it is not blanket approval for high-risk loads. |
| Stability and security | The notes describe general improvements. | They do not enumerate every change or establish that unrelated products are updated. |
Does Apple Home, Alexa, Google Home or SmartThings show the new data?
Do not copy an ecosystem-compatibility table from one date and treat it as permanent. TP-Link’s ecosystem feature comparison is explicitly subject to change. Its January 2026 version does not yet reflect the August release uniformly; the new firmware notes specifically name SmartThings and Home Assistant as having functional Matter energy monitoring at the time of publication, with implementation still evolving. That is TP-Link’s vendor statement, not an independent WesternTechy cross-platform test. Check your controller’s release notes and the actual entity or energy page before you plan an automation around it.
A Matter label describes a supported control standard. It does not promise that every receiving app exposes every data point, or that a Matter bridge translates every vendor-specific feature. Our Smart Home Compatibility Matrix separates hardware identity, transport, controller, feature exposure, and local ownership, so you can record the specific answer for your own installation.
Before updating, record your existing readings and setup
A firmware update is not a substitute for a baseline. Write down the plug’s model, hardware version, current firmware, household account, connected load, and the energy history you care about. TP-Link’s earlier KP125M firmware notes warn that historical energy data may be cleared after an upgrade; the August 2026 notes do not themselves say that every history record will be preserved. Take screenshots or export what the app currently allows, without placing passwords or recovery codes in a shared document.
TP-Link documents updates through the Kasa app and Tapo app; use the current official instructions for your setup rather than a third-party firmware file. Keep the plug powered during the update and wait for the app to report completion. An update may arrive progressively, so two plugs with the same retail name need not display it simultaneously. If the update is unavailable, confirm the exact hardware label and region first, rather than trying unrelated firmware.
A practical verification sequence
- Match the hardware. In the native app and on the physical label, record KP125M, region, and hardware V1 or V1.6. Read the corresponding official release notes.
- Record a baseline. Note the current on/off state, app-visible watts and accumulated kWh for a manufacturer-approved, low-risk load, plus your firmware version.
- Update through the official app. Keep power stable; do not interrupt the installation.
- Confirm firmware. Reopen Device Settings after the update and check the installed version, rather than assuming a completed download implies a completed installation.
- Look for actual data in the receiving platform. Does the Matter app show power and energy readings, historical data and usable entities? Record missing fields instead of guessing from its on/off tile.
- Compare over time. Use an approved, steady load and a meaningful observation period. Watts are an instantaneous power reading; kWh accumulates energy. A one-off difference does not establish a defective meter.
Our safe energy-measurement Guide explains how to record a kWh baseline and use your real electricity tariff. The Budget Calculator can put device costs, recurring fees and a contingency into the same plan.
What this firmware does not change
A new data field or software protection feature does not change an outlet’s regional voltage, the connected appliance’s starting current, or whether unattended operation is safe. TP-Link’s load compatibility guidance warns that motor loads and model-specific ratings require separate checking. Do not treat this update as permission to use a generic smart plug for a portable space heater, freezer, air conditioner, washing machine, pump, or critical equipment.
Nor is power monitoring automatically a washer-finished alert. A receiving controller may show watts and kWh without exposing a threshold trigger; some automation features remain native-app or platform-specific. Use your equipment’s approved status reporting instead of installing an unsupported switching relay merely to get a notification. If a device is to be left for another resident, document the owner and authorized reset/transfer procedure in the Device Inventory & Account Transfer Tracker.
Source notes
This briefing was prepared from TP-Link’s U.S. KP125M V1 and V1.6 firmware histories, its Matter ecosystem feature table, and official Kasa firmware-update instructions. The manufacturer may revise compatibility or rollouts after the September 27, 2026 review date. WesternTechy has not run a lab comparison, confirmed every regional SKU, or measured the update’s accuracy on a physical KP125M.