above board 
adjective & adverb
Legitimate, honest, and open: [as adjective]: certain transactions were not totally above board [as adverb]: the accountants acted completely above board...
- By offering a new package of preferential terms for the 50-75 age group, they are open and above-board about their intention to make huge profits out of this sector while catering to their specific needs.
- I have always intended to create this remake in an honest and above-board manner, respecting the copyrights and trademarks involved, so I hope that we will be allowed to proceed with it.
- But any time we can let the public know that what we're doing is above-board, honest and balanced, it helps our profession in the long run.
Synonyms
honest, fair, open, frank, straight, overt, candid, forthright, unconcealed, trustworthy, unequivocal;
legal, legitimate, lawful, licit
informal legit, kosher, pukka, by the book, fair and square, square, on the level, on the up and up, upfront
honestly, fairly, openly, frankly, overtly, candidly, forthrightly, unequivocally;
legally, legitimately, lawfully