mail MD tax return but pay due in credit card?

[steo79]

I e-filed my federal income tax return and paid the due with credit card. For the Maryland tax return, I'd like to mail it. But I'd like pay the due with credit card instead of check. Maryland allow to do it. My question is, do I just mail it then pay online OR do I need to include a receipt of the payment something like that with the mailing?

[RobertG · Accepted solution]

Just mail it and pay online. 

Maryland will match the return with the payment when they process your return.

[fanfare]

you have until April 15 to pay, regardless.