If you have a Disability Parking Permit, you may apply to the Swedish Tax Agency to exempt your vehicle from the tax obligation. The application form is available from the link below:
Application for release from congestion tax (in Swedish only)

This form can also be ordered via Customer Services on +46 (0)771-29 29 29. Customer Services will also answer any questions that you may have.

Please note that the exemption from the tax obligation applies for as long as the parking permit is valid. This exemption may still apply if your vehicle was exempt from the tax obligation during the congestion tax trial. This is why you should check the period covered by your decision from the Swedish Tax Agency (Congestion tax – release from tax obligation) before submitting a new application.

You will probably have to reapply if you have replaced your vehicle since the end of the congestion tax trial. You are not required to produce a physician's certificate when applying; you will, however, have to provide a copy of the front of your parking permit. When applying, the person may choose which vehicle should be exempt (the Swedish Tax Agency may exempt two vehicles from the tax obligation if there are exceptional grounds).

Congestion tax will be charged when you are travelling in another vehicle. There is no requirement stipulating that a person with a disability must personally own the particular vehicle in question.