No. Article 4 of Qatar's Labour Law makes it very clear that the rights prescribed by the law represent the minimum entitlements for all workers. Any contract terms or conditions that attempt to give you fewer rights than the law guarantees are considered null and void — even if you voluntarily agreed to them and even if the contract was signed before the law came into force.
This is an important protection for expat workers. It means that if your contract, for example, provides fewer annual leave days or a lower end-of-service benefit than the law mandates, those specific clauses cannot be enforced against you. You would still be entitled to the legal minimum.
Practically speaking, you should familiarise yourself with the key minimums under the law — including working hours, leave entitlements, and gratuity — so you can identify if your contract falls short. If you believe your employer is offering below-minimum terms, you can raise a complaint with the Ministry of Labour.
This is general legal information, not legal advice. For advice on your specific situation, consult a lawyer licensed in Qatar.