We're implementing the recent HMRC changes to electric vehicle mileage reimbursement rates that came into effect from 1st September 2025. HMRC announced these changes on 22nd August, introducing split rates based on charging location: 8p per mile for home charging and 12p per mile for public charging.
This enhancement allows you to accurately reimburse employees based on where they charge their electric vehicles, ensuring legislative compliance whilst maintaining P11D Section E classification.
What is this feature for?
The new EV split mileage functionality enables your organisation to charge different mileage rates based on where electric vehicle miles were charged. This feature is based on changes to UK legislation and can be configured according to your requirements.
Key benefits:
Complies with the latest HMRC guidelines for EV reimbursement.
Maintains existing audit trail and reporting capabilities.
Offers flexibility to use traditional threshold rates for some vehicles if preferred.
How it works
When employees submit mileage claims for electric vehicles:
They enter the total miles travelled and the miles charged away from home (public charging).
The system automatically calculates home-charged miles: total miles - away miles = home miles.
The blended reimbursement is calculated using: (away miles × public rate) + (home miles × home rate).
The calculation breakdown is displayed transparently on the expense claim.
For example: An employee travels 11 miles total with 1 mile charged away from home:
1 mile × 12p (public rate) = £0.12
10 miles × 8p (home rate) = £0.80
Total reimbursement = £1.20
Implementation timeline
Development prioritisation: This has been fast-tracked due to the short notice period from HMRC.
UAT availability: 30th October 2025
Live release: 6th November 2025
Mobile app enhancements: Early 2026
Note: The web app version will provide mobile access from the initial 6th November release, so employees can submit claims via mobile browser while we complete the native app updates.
How to set it up
Step 1: Enable the feature
The enhancement operates behind a feature flag (exp-ev-split-mileage) and must be activated for your organisation. To request activation, please raise a support ticket.
Step 2: Configure the Car Rates Configuration widget
In the administrator dashboard, you'll need to set up the new widget:
Navigate to Dashboard Configuration
Select the Car Admin row from the Dashboard Tabs grid
Search for 'car' in the Tab Widgets section
Toggle the Car Rate Configuration widget on
Step 3: Set up your EV mileage rates
Access the new rates configuration screen:
Navigation: Administrator Dashboard > Car Rates Configuration Widget > EV Mileage Rates.
Setting rates:
Rates are configured by vehicle type (e.g., "Electric")
You can set different rates by company code and car ownership (private/company)
Each rate requires an effective date (when it comes into force)
Specify both the home charging rate and the away from home rate
Important considerations:
Rates where the company field is left blank apply to all companies unless overridden by a company-specific rate with a more recent effective date
You can edit or delete rates, though we recommend not modifying rates already in use
If you add an EV rate for a vehicle type that already has traditional threshold-based rates, you'll receive a confirmation warning
The system will use whichever rate (EV split or threshold) has the most recent effective date for a given vehicle type
Step 4: Employee access
Once configured, employees will see the new field automatically:
Navigation: My Dashboard > Expense Report > New Expense Report > Add expense detail > Select mileage pay code
When creating a mileage claim for an electric vehicle, the Miles Charged Away from Home field will appear
This field only displays if there's a valid EV rate for the selected date range
Technical changes
The solution includes updates to:
Calculation engine with automatic blended rate calculation
Portal input screens (desktop and mobile web)
Back office validation and warnings
Enhanced vehicle configuration supporting dual rate fields
Modified mileage entry interfaces
The calculated values are stored in the same fields used for existing threshold rates (mile_unit and mile_unit_rate on trip and claim detail tables), ensuring compatibility with existing Insight reports and audit processes.
Important validation rules
Employees must split mileage claims into separate items if the rate type changes during the trip period (e.g., if switching from threshold to EV split rates mid-journey)
Miles charged away from home cannot exceed total miles
The EV rate must be valid for the entire date range of the expense claim
If an EV rate is deleted, claims will automatically fall back to traditional threshold rates
Expense claims already submitted and processed for September and October will not have these split rates applied retrospectively. However, you can set the effective date as 1st September 2025, meaning any unsubmitted trips will automatically use the new rules when processed
Mobile access
Initial release (6th November 2025): Full functionality available via mobile web browser
Native mobile app: Enhanced features will be available in late November or December 2025
Further information
To have this feature enabled for your organisation, please raise a support ticket.
For technical queries or assistance with configuration, our support team is ready to help.