According to Kipa, if you are an esrog or lulav merchant you had better watch out.. Kipa is reporting that undercover tax officials are going to "4 species markets"  around the country and catching merchants who are not registered with the tax authorities and/or doing businesses without paying the necessary taxes.

They say the lulav-esrog market is mostly a black market, with nearly the entire thing being off the books. Tax officials have supposedly been going to markets in various towns and after questioning sellers about getting receipts for purchases are slapping fines on the sellers.

I remember a few years agon in Bet Shemesh the mayor decided to crack down on the black market, to a certain extent. People who would set up booths without paying the necessary fees to the Iryah would get shut down and fined. There was an outcry, but they still seem to do it. The other outcry that was ignored was  from the merchants who claimed it to be unfair - the ones with booths are being stopped, but many sell otu of their homes, and the ads are all over the neighborhood, but no supervisors go to those houses to shut down those merchants or to fine them..

So, watch out. Or register your business and give receipts.