In 2003, Betts was suspended from the House of Commons for seven days for irregularities involving the employment and visa of Jose Gasparo, a Brazilian student with previous experience as a male escort. The Daily Telegraph newspaper reported on the 10^th July 2010 that Betts' partner and parliamentary assistant, James Thomas, had tried to edit this fact from Betts' English Wikipedia page in an attempt to cover it up.

Betts employs his partner as his Senior Parliamentary Assistant on a salary up to £45,000. He was listed in articles in The Daily Telegraph and The Guardian which criticised the practice of MPs employing family members, on the lines that it promotes nepotism. Although MPs who were first elected in 2017 have been banned from employing family members, the restriction is not retrospective - meaning that Betts' employment of his partner is lawful.

Betts was found guilty of breaching the MPs' code of conduct, with the Standards and Privileges Committee stating that he had acted "extremely foolishly" and had risked damaging public confidence in the integrity of Parliament. Particular concerns involved his failure to disclose Gasparo's background to parliamentary authorities and the fact that Betts had knowingly photocopied an altered document on Gasparo's behalf. Betts gave an "unreserved apology" in a personal statement to MPs when the report was published.

Betts was subject to criticism for his accommodation expenses after he had previously campaigned for an increase in MPs' entitlements on the ground of "hardship". It was reported by The Times that Betts had "flipped" his designated second home to Yorkshire before buying a "country estate" there, before "flipping it" back to London and taking out a larger mortgage on his flat there. Betts denied wrongdoing, arguing the Yorkshire property had been "two dilapidated listed buildings" and that when he became a whip he had to declare his main residence as his London flat.

Betts was criticised by the British Medical Association for going to Portugal with 15 fellow MPs on an all-expenses trip paid for by the fast food chain McDonald's. Betts responded that if MPs had a "puritanical" attitude about food then people would ignore what they said.

Betts faced further criticism in 2010 after it was reported that he was one of eight MPs who were renting out a "second home" in London while claiming for the cost of renting a "third home" in the city at taxpayers expense. Although legal, critics argued the "loophole" was allowing MPs to increase their income after the rules on parliamentary expenses were tightened.