APR disclosures for open-end credit have different rules than closed end credit. You will want to review 226.14 and its commentary.
The "access fee" you are referring to is a transaction fee under Reg. Z. For each billing period any transaction fee will be calculated into the APR. So one billing period you could have an APR of 18% and the next billing period you could have an APR of 23.5%.
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The opinions expressed are mine and they are not to be taken as legal advice.