adam smith

As I owe below £3k and have a permanent job I requested my self-assessment return under-payment be collected via PAYE in 24/25. My self assessment statement received recently does not mention PAYE option but asks for payment of full amount by Jan deadline. What happens is if I pay upfront and then my tax code changes to collect it through PAYE (i pay twice!) or if I don't pay in full now and assume that it will come via PAYE but doesn't I get a late payment penalty! Statemen is not clear on this at all. Any advice appreciated!!