If you have already filed your initial 2290 for the current tax year and need to add another vehicle or have acquired a new vehicle you will need to create a new 2290 return with only the new vehicle on it.
You do not need to enter any of the vehicles you have already filed for on this return, only those you have not filed for yet.
The end result should be that you have separate Stamped Schedule 1s from each filing but all should be current with the filing
To File a Form 2290 for your heavy vehicle, you can use the IRS-Authorized E-File Provider: ExpressTruckTax.com
The process takes only a few minutes to complete, but if you have any questions, you can contact the Truck Tax Team at 704.234.6005