Just got married last year and now first time filing under married category.

If my wife is earning below 2500, should i submit mine and hers together?

what areas can i claim rebate for spouse?

Thank you

Nowadays, company, sole-proprietorship, even PCB, all are paying ahead or pre-installment one.

Company every year even before new financial year begin, they need to provide forecast for their next year profit, and paying tax ahead (some sort like PCDB for individual)

With the current new system, there is little tax being paid when the assessment year ended.

It is still the same. Pay as you earn.

maybe you have other income such as rental income

If you are under employment, impossible IRB ask you to pay instalment. I don't know what is the documents you received. Maybe
1. its an instalment for your arrear taxes
2. you have undisclosed income.

Since you like 4 letters word so much , you settle it yourself

The PCB (monthly tax you pay to IRB) is based on your monthly income. There is a table for that but I couldn't find inside IRB web site at this moment. Usually your HR has the table. If that month you earn bonus, for sure your PCB for that month will be crazy.

Let's say in Feb:
monthly salary = RM3000
Bonus 2 month = RM6000
Total gross income = RM9000

So the PCB for Feb is similar like you earn RM9000 x 12 income. However next month, March, your PCB will definitely be reduced like you earn RM3000 x 12.

That's why suddenly you need to pay huge amount when you receive bonus for that month. It doesn't matter the bonus for which year. IRB just concern you receive this amount of money in that month, so your PCB will be changed.

I know it sound crazy and unfair, but this is our IRB.

You can calculate your monthly PCB here:
http://ekl.hasil.gov.my/pcbcalc/

Sometimes, we feel it is good not to get bonus because most of the bonus we receive will go to IRB. Don't be too happy and excited when you get bonus.