Plan 1 direct debit payment query

whyareallthegoodusernamestaken

I'm reaching the end of my plan 1 loan and I'm being pressured to switch to pay by direct debit.

My thoughts are:
*PAYE deductions are pre-tax
*Direct debit deductions will be post-tax from my bank account
*I pay roughly 30% overall tax rate, therefore switching to DD will cost me 30% more, vs the benefit of not overpaying and not having to wait for a refund

Even if I have PAYE payments taken for 11 months after finishing (unlikely), I (personally) can afford that, simply because I'm used to my current take-home pay and I'm going to get the money back eventually. 

Only downside i can see is that i won't be paid interest on the money I've "loaned" to SLC, but the interest I'd get is pretty low anyway, and certainly less than the 30% tax cost from paying by direct debit.

Is my thinking right, or have i misunderstood the way repayment by direct debit works?

Ed-1

whyareallthegoodusernamestaken said:

I'm reaching the end of my plan 1 loan and I'm being pressured to switch to pay by direct debit.

My thoughts are:
*PAYE deductions are pre-tax
*Direct debit deductions will be post-tax from my bank account
*I pay roughly 30% overall tax rate, therefore switching to DD will cost me 30% more, vs the benefit of not overpaying and not having to wait for a refund

Even if I have PAYE payments taken for 11 months after finishing (unlikely), I (personally) can afford that, simply because I'm used to my current take-home pay and I'm going to get the money back eventually. 

Only downside i can see is that i won't be paid interest on the money I've "loaned" to SLC, but the interest I'd get is pretty low anyway, and certainly less than the 30% tax cost from paying by direct debit.

Is my thinking right, or have i misunderstood the way repayment by direct debit works?

PAYE deductions are not pre-tax.