Is statutory maternity pay funding taxable income?
Assuming you are talking about the small employers rebate and the taxation of profits (sole trade, partnership, LLP or LTD) it is in effect a reduction in your overall NI payments. You have a smaller class 1a charge, you cannot deduct the full 1a charge in your tax calculation and "add back" the compensation.
Yes it is accounted for through your monthly PAYE payment and P35 but it is not tax free.
If it was tax free we could all introduce tax saving schemes such as "Get pregnant at work" or maybe "**** a ****" no best leave that alone.