AER Reimbursement Calculator For Electric Cars
Advisory Electric Rates (AERs) are HMRC-recommended mileage rates for employees using electric company cars. They can be used by employers when reimbursing business mileage in fully electric company cars, with separate rates for electricity charged at home and through public charging networks.
Our AER Reimbursement Calculator helps you estimate the actual electricity cost of an electric car journey and compare it with the current HMRC Advisory Electric Rate. You can select your vehicle, adjust the calculation for temperature and driving conditions, and enter the electricity tariffs you pay for home and public charging.
If your journey involves more than one charging method, you can add multiple journey sections. This allows you to account for electricity charged at home, on public or kerbside chargers, and at rapid or ultra-rapid charging stations.
Vehicle efficiency can vary depending on temperature, road type, driving conditions, speed and other factors. Our calculator therefore allows you to adjust the estimated efficiency to give you a more realistic indication of the electricity used during your journey.
Once you have entered your journey details, the calculator shows your estimated total charging cost, energy consumption, cost per mile and the AER amount calculated using the current HMRC rates.
The calculator is intended as a guide only. Actual electricity consumption and charging costs will vary depending on the vehicle, driving conditions, charging tariff and other factors. Always check the latest HMRC guidance before submitting a business mileage claim.

Commercial Vehicle Contracts – AER Reimbursement Calculator
Estimate the electricity cost of an electric car or van journey and compare it with the current HMRC Advisory Electric Rate (AER).
1. Select Your Vehicle
2. Adjust For Driving Conditions
3. Enter Your Charging Costs
4. Build Your Journey
Journey Results
| Journey Section | Distance | Charging | Energy | Rate | Actual Cost | AER |
|---|
AER Rates And Mileage Allowance Payments Are Different
The HMRC Advisory Electric Rate is specifically for employees using fully electric company cars. It should not be confused with the Approved Mileage Allowance Payment (AMAP) rates used when employees use their own cars or vans for business journeys.
For the 2026/27 tax year, the approved mileage rate for cars and vans is 55p per mile for the first 10,000 business miles and 25p per mile thereafter. Different rules apply depending on who owns or provides the vehicle, so businesses should check the latest HMRC guidance before calculating or submitting mileage claims.
What Is The HMRC Advisory Electric Rate?
The HMRC Advisory Electric Rate (AER) is a recommended mileage rate used when employees drive fully electric company cars for business journeys. It allows employers to reimburse the cost of electricity used for business travel without having to calculate the precise electricity cost of every individual journey.
From 1 September 2026, the HMRC Advisory Electric Rate is 7p per mile for home charging and 15p per mile for public charging. These rates can change when HMRC reviews its advisory fuel rates.
How Does Electric Vehicle AER Reimbursement Work?
When an employee uses a fully electric company car for a business journey, their employer can reimburse the electricity cost associated with that business mileage using the applicable HMRC Advisory Electric Rate.
The current rate depends on where the electricity used for the journey was charged. From 1 September 2026, HMRC’s rate is 7p per mile for home charging and 15p per mile for public charging.
For example, 100 business miles at the home charging rate of 7p per mile would result in an AER reimbursement of £7.00. At the public charging rate of 15p per mile, the same 100 miles would result in £15.00.
The actual cost of charging an electric vehicle can be higher or lower than the AER reimbursement. This depends on factors including the vehicle’s efficiency, electricity tariff, driving conditions and where the vehicle is charged.
How To Use Our AER Reimbursement Calculator
Our AER Reimbursement Calculator allows you to estimate the electricity cost of an electric vehicle business journey and compare it with the applicable HMRC Advisory Electric Rate.
1. Select Your Vehicle
Choose your electric vehicle or enter the vehicle’s efficiency if you already know it.
2. Adjust For Driving Conditions
Select the temperature and type of driving to account for changes in real-world EV efficiency.
3. Enter Your Charging Costs
Add the electricity tariffs you pay for home, public and rapid charging.
4. Add Your Journey
Enter the distance travelled and select the charging method used. You can add additional journey sections if different charging methods were used.
5. Check Your Results
The calculator shows estimated energy consumption, charging cost, cost per mile and AER reimbursement.
6. Download Your Results
Download your calculation as a CSV file for your records or business mileage administration.
AER Reimbursement FAQs
From 1 September 2026, the HMRC Advisory Electric Rate is 7p per mile for home charging and 15p per mile for public charging.
Yes. The Advisory Electric Rate is used when calculating electricity reimbursement for business journeys in fully electric company cars.
HMRC currently provides a separate public charging rate of 15p per business mile. The appropriate rate should be used according to the circumstances of the journey and the latest HMRC guidance.
Not necessarily. The AER is an advisory mileage rate rather than a calculation of your exact charging cost. Your actual cost will depend on factors such as your vehicle’s efficiency and electricity tariff.
Yes. You can use the calculator for an electric car or van by selecting the appropriate vehicle or entering its efficiency figure.
HMRC reviews its advisory fuel rates periodically, so the rates can change. Always check the latest HMRC guidance when calculating or processing a mileage