Most efficient way to pay child maintenace to ex

[mudskipper]

If childcare vouchers are applicable to your situation, you could presumably still get those through your company and reduce the maintenance by a similar amount?

[ASB]

Maintenance payments are not taxable on the recipient. They are simply made out of the payers personal funds. Make sure you draw up a proper agreement; Child Maintenance Options - Information and Support on Child Maintenance

You may be on reasonable terms now, but that can often change down the line. A proper agreement can protect you from the fallout. If you are both genuinely on good terms then surely you will both understand the need to protect your individual and the childrens interests.