# Thread: VAT Change (2007 SP1)

1. ## VAT Change (2007 SP1)

As some people may know, VAT has changed in the UK from 17.5% to 15%. I'm in the process of creating a small Purchase Order Database, and I've often read that you should not store totals, etc, in Fields but instead use Calculations in Queries, Forms, etc.

Hans very kindly provided the Formula for doing this on a Form, but with the change of VAT, will this not throw records out in future when VAT changes back to its normal rate.
Eg
Someone buys a Product at £100. This is stored in a Value Field. If VAT is to be included, then the Calculated Total Value displays as £115.00.

But, eg, in 2 years, if VAT reverts to 17.5%, then this Calculated Total will display as £117.50, which wouldn't be right, as only £115.00 was paid for the item.

What's the best way to circumvent this problem? Should I just go ahead and create a Field called Total?

If so, do I then use an OnClick Event to Update this Field, eg.

Dim db As Database
Dim strSQL As String
If me.VAT = true Then
Set db = DBEngine(0)(0)
strSQL = "INSERT INTO [tblPurchaseOrder] ([TotalAmount]) VALUES('[InvoiceAmount]*(1+IIf([VAT],0.15,0))');"
db.Execute strSQL
Set db = Nothing
Else
Response = acDataErrContinue
End If

I could then just change this Event Code whenever VAT changes?

BTW, I don't think the above code is exactly right, so suggestions are appreciated!

Brian

2. ## Re: VAT Change (2007 SP1)

I store the VAT (or GST) rate used for each transaction in a field associated with the transaction record. So calculations are based on the transaction VAT(GST) field, rather than the more general current value.

3. ## Re: VAT Change (2007 SP1)

Thanks John

I've changed the Yes/No Checkbox to a Number Field and have set the Default Value to 15, so the Total Amount is now a calculation of those combined.