For filling itr 4s as per section 44ae

Sir, My client has a income from giving rent a tata ace to a company. He has received his payment by cheque. Now my question is that- Suppose he received around Rs. 25,000 pm and shows his income in ITR 4s as per section 44AE i.e 7,500 per vehicle p.m then any problem will arise from IT dept. As his receiving amount is greater than showing amount. Pls clarify.