The project was offered to novelist Ōtarō Maijō in December 2015, with character designs following in 2017; in its early planning stage the series was titled 'ALIEN THURSDAYYY' and featured a 'Thursday detective' who entered a killer's murderous intent using a system called 'Jupiter Z'.

Director Ei Aoki, known for Fate/Zero and Aldnoah.Zero, teamed up with writer Ōtarō Maijō, known for novels like Sukisukidaisukichoaishiteru and Disco Tantei Suiyōbi, to create the series for animation studio NAZ.

The opening theme 'Mister Fixer' by Sou topped the Japanese-language chart on QQ Music for four consecutive weeks.

The names of the id-well detective personas (Sakaido, Hijiriido, Anaido, Hakaido, Uraido) are wordplay combining the Japanese word for 'well' (ido/ido) with each character's name, and the concept 'Id' itself is described as a triple meaning referencing psychoanalysis's id, the Japanese word for well, and 'different land' (異土).

The series was a nominee for the Media category of the 52nd Seiun Award in 2021.

A manga sequel titled ID:INVADED #BRAKE-BROKEN, illustrated by Yūki Kodama with story by Ōtarō Maijō, began serialization in Young Ace magazine in November 2019, starting before the anime even aired, and was only later revealed to be a direct sequel to the anime's story.

Two exclusive short stories written by Ōtarō Maijō, 'Inami-san to Kazuta-kun' and 'Memories of Love', were bundled as booklets with the Blu-ray box sets; 'Memories of Love' is actually a novelization of a scrapped flashback scene originally planned for episode 10.

After the anime's broadcast, Maijō wrote a series of unofficial spin-off short stories on Twitter under the title 'ID OFF' between August and September 2020, which were later revised and republished as the collection 'Tanpen Shichibōsei' (Seven-Pointed Star Stories) in the magazine Gunzō and as a standalone book in 2022.

A separate ongoing web video series called 'ID:INFUSED', written by Maijō with art by character designer Atsushi Ikariya, depicts the show's characters drinking alcohol named after themselves, and has been posted on Twitter in installments since December 2020.