Whether or not your account is using the Free API is determined by the product code that you use when you log on. It's 22 for the free API. To use the paid API, you need to pay a subscription and you get a different product code. Everything in the manual is about the free API (the paid one only really differs in fewer restrictions on fetching market data). The specifics of all restrictions in market data fetching escape my memory but they are listed in the Appendices of AEB and on the Betfair website. It's probably worth checking - from memory, you are limited to 5 different markets per minute, so if you are trying to fetch data from more than 5 markets in a minute, that will likely be the problem. Sys.sleep(0.2) means that you can call 5 markets in a second...