Praise be to Allah.
It is mustahabb (recommended, encouraged) for the person who is praying alone to say the Adhaan and Iqaamah, because of the general meaning of the reports that refer to them.
Al-Shaykh Mansoor al-Bahwati (may Allaah have mercy on him) said:
“They (the Adhaan and Iqaamah) are Sunnah (for the person who is praying alone) because of the general meaning of the hadeeth of ‘Uqbah ibn ‘Aamir, who said that the Prophet (peace and blessings of Allaah be upon him) said: ‘Your Lord likes it when a shepherd at the top of a mountain pass calls the Adhaan for prayer and then prays. Then Allaah says, “Look at this slave of mine, saying the Adhaan and the Iqaamah for prayer and fearing Me. I ask you to bear witness that I have forgiven My slave and will admit him to Paradise.”’” (Narrated by al-Nisaa’i). The Adhaan and Iqaamah are also Sunnah for travellers, because the Prophet (peace and blessings of Allaah be upon him) said to Maalik ibn al-Huwayrith and his cousin: “When you two travel, say the Adhaan and Iqaamah for prayer, and let the elder of you lead the prayer.” (Agreed upon). Mutaalib Oolaial-Nuha, part 1, Baab al-Adhaan.
It is makrooh (disliked) for him to neglect the Adhaan and Iqaamah.
Al-Shaafa’i (may Allaah have mercy on him) said:
“If a man neglects to say the Adhaan and Iqaamah when he is praying alone or in congregation, I regard that as makrooh, but he does not have to repeat the prayers he did without the Adhaan or Iqaamah.”