I have filed already, but the payment will not be direct debited from my account until the 15th of April. Can I edit payment method?

[DoninGA]

You would need to cancel your payment before you could change or edit your payment method.

See this IRS website for canceling a federal tax payment - https://www.irs.gov/payments/pay-taxes-by-electronic-funds-withdrawal

• Once your return is accepted, information pertaining to your payment, such as account information, payment date, or amount, cannot be changed. If changes are needed, the only option is to cancel the payment and choose another payment method.
• Call IRS e-file Payment Services 24/7 at 1-888-353-4537 to inquire about or cancel your payment, but please wait 7 to 10 days after your return was accepted before calling.
• Cancellation requests must be received no later than 11:59 p.m. ET two business days prior to the scheduled payment date.

You can also use this IRS website to make federal tax payments - https://www.irs.gov/payments