A columnist warns that resigning before the new employer has signed a contract can backfire: the offer may be withdrawn after the 30-day notice is already given. Before handing in notice, sign the new contract and keep a copy as evidence for the Labour Court. Watch for clauses that charge a guarantee deposit unrelated to the job, withhold the final salary if probation is failed, or forfeit the deposit if you leave within one year. An employer that refuses to give a copy of the contract is a warning sign.