The Embassy of Sudan in Washington lists, for business visas, a signed form, a passport valid at least 6 months, a photo and a sponsor letter, with a US$154 fee and up to 10 working days. The Investor Guide 2025 states that an investor's visa is obtained on arrival at the airport or through an embassy, and that the first visit is for 2 months, extendable.
Current rules could not be confirmed. No official e-visa portal was found. A 2022 US Commerce guide mentions arrival visas only at Khartoum airport; which airports handle arrivals now is not verified.