Compliance is the most critical factor to avoid customs seizure. For the US market, products must comply with the ASTM F963-17 (Standard Consumer Safety Specification for Toy Safety) and the CPSIA (Consumer Product Safety Improvement Act). For the EU, EN71 Parts 1, 2, and 3 are mandatory to ensure physical safety, flammability resistance, and non-toxicity. Additionally, since it mimics currency, you must ensure it adheres to anti-counterfeiting laws; for example, US regulations require toy money to be one-sided or significantly larger/smaller (at least 150% or less than 75%) than real currency to prevent fraud.