Fasting ‘Ashoora’ for one who still owes days from Ramadaan

Dear Brothers & Sisters,
As-Salaamu-Alaikum wa Rahmatullahi wa Barakatuh. (May Allah's Peace, Mercy and Blessings be upon all of you)
One of our brothers/sisters has asked this question:

I still have days to make up for Ramadaan and I want to fast ‘Ashoora’. Is it permissible for me to fast ‘Ashoora before I have made up the fasts I owe? Can I fast ‘Ashoora’ and the eleventh of Muharram with the intention of making up the Ramadaan fasts, and will I get the reward for fasting ‘Ashoora’?.

(There may be some grammatical and spelling errors in the above statement. The forum does not change anything from questions, comments and statements received from our readers for circulation in confidentiality.)
Check below answers in case you are looking for other related questions:
Does praying Tahiyyat al-Masjid mean that one does not have to pray Sunnat al-Fajr?
Should he pray four rak’ahs before and after Jumu’ah as he does with Zuhr prayer?

Answer:

Praise be to Allaah.

Firstly: 

You should not observe voluntary fasts when you still owe one or more days from Ramadaan, rather you should start with the fasts that you owe from Ramadaan, and then observe voluntary fasts. 

Secondly: 

If you fast the tenth and eleventh of Muharram with the intention of making up days that you owe from Ramadaan, that is permissible and will make up for two of the days that you owe. The Prophet (peace and blessings of Allaah be upon him) said, “Actions are judged but by intentions, and every person will have but that which he intended.” 

Fataawa al-Lajnah al-Daa’imah, 11/401 

We hope that you will have the reward for making up the missed fast and the reward for fasting that day. 

Fataawa Manaar al-Islam, by Shaykh Muhammad ibn ‘Uthaymeen (may Allaah have mercy on him), 2/358.

Whatever written of Truth and benefit is only due to Allah's Assistance and Guidance, and whatever of error is of me. Allah Alone Knows Best and He is the Only Source of Strength.
Your brother and well wisher in Islam

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