A compound tax is a tax stacked on top of a primary tax. This is different than just applying 2 different taxes to an item. Here's an example:
Applying 2 Different Taxes: Item Cost: $100.00 1st tax of 5%: $5.00 2nd tax of 10%: $10.00 Total: $115.00
Applying Compound Taxes: Item Cost: $100.00 Primary tax of 5%: $5.00 Subtotal: $105.00 Compound tax of 10%: $10.50 Grand Total: $115.50
To apply compound taxes in LessAccounting, you'll need to first figure out your subtotal, then apply a tax (as set in up Settings > Sales Tax) to that amount.