A Legal Tender is any item as money use as means for the exchange of goods and services, issue by a soverreign authority. What makes any meduim of exchange of goods and srvices different from what money as a legal tender is the sovereign status odmf the issuing authority. So, yes an authority like ECOWAS can issue a bill call money, like any bank can issue a check as a bank note but because the issuing authority has no sovereign status, the item will not be a legal tender. Therefore every one of the 15 ECOWAS nember state can have, circulate and float its own currency as its money because each is a sovereign authority.
What confuses most o thef you is, because each of 15 countries is a sovereign authority, if the 15 sovereign coutties join together to form a body, then the authority automatically become sovereign. The fact is, so many sovereign bodies coming together to form a body doesnt automatically make the authority of the new body sovereignty, even if the formative entities wish it to be sovereign. The intetesting thing is, the 15 heads of member states of the ECOWAS desperatly want the ECOWAS authority to be sovereign like the EU but the approach being employ does not result in what is wanted. The ECOWAS Common passport is clealy an evidence of what the fate of the new ECOWAS Common Currency will be. The difference between a sovereignless passport and sovereignless Common currency is, passport is only meant for individuals who are traveling. Money is a different ball game because everyone uses it, whether traveling or not.
In fact money decides everything in the life of the modern man. So if the money is wrong then the whole economy of 5 major ECOWAS countries will be disastrious. I am a citizen of Ghana who will directly be affected if my fragile legal tender which is the Cedi is replace with ordinary ECOWAS paper. If I can see such danger, then the consitution of Ghana instruct me to stamd up against such economic suicide. I pray to all decent West Africans to join me in making the just truth prevail. Its time to do what is right for us own good.