Given the high volume of transactions in the digital economy, this area can be considered as one of the tax bases for generating revenue for the government. Therefore, planning for tax collection from this area is necessary in Iran. Currently, there are many challenges in the field of tax collection, identifying which is the first step towards planning and optimal use of this revenue capacity. This article aims to identify tax challenges related to the specific characteristics of the digital economy, and especially cryptocurrencies. First, using the meta-synthesis method, the general challenges related to the nature of the digital economy were identified, and then using semi-structured interviews with 16 experts from the country's Tax Affairs Organization, the challenges related to cryptocurrencies were identified. After identifying the challenges, these factors were classified into four categories based on the criteria of importance and urgency: critical challenges, strategic challenges, urgent but low-impact challenges, and challenges that can be ignored for the time being. Accordingly, the main tax challenges in the field of cryptocurrencies include the lack of adequate regulations, problems with transaction tracking, lack of technical infrastructure, and lack of access to sufficient data. The implementation priorities of policies and suggestions for improving these issues are detailed in the article.