It depends on what's being paid.
Your core payment — your rent, mortgage, or car payment — is always split into two payments. There's no way to send that payment in full through your Split Pay account and routing numbers. If you want to pay a month's rent, mortgage, or car payment in full, use a different payment method in your portal (your regular bank account or debit card).
But not every charge that comes through your Split Pay account and routing numbers is your core payment. Split Pay can tell the difference between your main payment and other charges your portal might pull — like a security deposit, a move-in fee, or a one-time escrow or account charge — and handles them automatically:
Charged on its own (separately from your main payment): Split Pay sends it in full — it won't be split.
Charged together with your main payment in a single pull: Split Pay splits the combined amount, as long as the total is within your approved Split Pay amount.
This works once you've already split a valid payment — your Split Pay account and routing numbers operate within your active Split Pay setup.