The Ain has several problems as a source. The quantitative data is skewed as it was not collected uniformly from all provinces. For instance, detailed information about caste composition of zamindars is available for many subas but not for Bengal and Orissa. Similarly, while fiscal data is rich, prices and wages are not well documented for all areas. The data on prices and wages mainly pertains to areas around the imperial capital of Agra, making it of limited relevance for the rest of the country. Additionally, there are numerous errors in totalling due to slips of arithmetic or transcription by Abu'l Fazl's assistants.

Historians deal with these problems by noting that the Ain was revised five times by the author, showing his caution and search for authenticity. Oral testimonies were cross-checked and verified before being incorporated as facts. In quantitative sections, all numeric data were reproduced in words to minimise transcriptional errors. Historians point out that the detected errors are generally minor and do not detract from the overall quantitative veracity of the text.