If "for reasons beyond its control" Russia was unable to make payments or interest in the currencies the bonds were issued in, dollar and euro, payments can be made in dollars, euros, British pounds or Swiss franc, the documentation shows.
Crucially, the rouble is listed as an alternative currency option for bonds issued since 2018, JPMorgan notes.
Because most of the eurobonds have a grace period of 30 days on both principal and coupon payments, Morgan Stanley calculates the earliest possible default could be April 15, when the grace period expires on the 2023 bond coupon.
Meanwhile default fears have also crept into the $35 billion market of Russian corporate debt. State-controlled Gazprom must repay a $1.3 billion dollar bond on March 7 -- a litmus test of Moscow's attitude towards foreign creditors.