Tax on irregular income

I am a freelance consultant and I get money on an irregular basis. Am I eligible to pay tax, and how would that be calculated? Following is an example of my income in a year:

Jan = R0
Feb = R50 000 (this the a sum of all clients for Feb)
March = R100 000
April = R0
May = R5 000
etc

Yes, you are taxed on your total income from March 1st to end February using the same tax rates as all other taxpayers. Please have a look at our SARS income tax calculator to see how much should be paid in tax on your overall income.