TM1 Forum

Dear all,

I am almost embarrassed to post this but while I am here I thought I may as well:

I need to add a very simple tax calculation to an existing rule but have a number of options and want some advice on what the best option is.

The tax calculation is adding 13.8% to the current calculation, so for example 100*(1+0.138) = £113.80

On the source input process I have added some code to populate a Y/blank attribute flag for ‘taxable’.

So my first thought was to create the Y/blank taxable attribute flag and in the rule put in an if statement saying if taxable = Y then multiply the value by 13.8% else just use the current calculation.

But then I thought why not instead just create a numeric taxable attribute and populate the attribute WITH 0.138 if it is taxable and get rid of the if statement in the rule altogether. So I just add to the existing rule * (1 + ATTRN(Dimension, Element, 'Taxable'))

I am thinking the second option is best, can anyone envisage any issues?

Please note the calculation is fed from a different element, so I don’t see that being an issue.

I would definitely skip the IF part and just calculate the tax by taking the taxable amount times the rate. I would go one step further and put it in a cube though with a time element because tax rates tend to fluctuate by time, as well as location. Just a thought.

Thanks Tom.

I have been told the rate won't change (I am gullible) but I have heard that one before and got burned (will I ever learn)! I was hoping to avoid referencing another cube in the rule but thinking about it I would be insane not to (which is worrying given I was I was going to)!

Now I am embarrassed!

Mark,
13.8% sounds suspiciously like Employers NI rate. If so:
- it changed from 12.8% in ( I think 2010)
- the employers amount is calculated as 13.8% above a threshold that changes year on year.

Hi Stephen,

It does sound suspiciously like the NI rate but alas isn't!

Not that you are to know but last year built I a pay model in TM1 so I know how the NI rate is calculated inside out and back to front.

Am hoping to gradually forget it all but just when you think you are out they drag you back in!

cheers, Mark

Mark,
No problems.