Access. Be prepared to be hassled over it. Be sure that your dog will be able to cope with the situation you are going to be in when out and about. Because people can send in $XXX to some online organization and get their untrained, unsuited to the job pet "certified" as a service dog, complete with impressive looking ID card and harness patches, there are a lot of dogs out there that shouldn't be. There was a case here in Texas just last month where a dog that was known to be aggressive/reactive, but who was out in public wearing a service dog vest, bit a little girl on the face.