While corporate hybrid note issues might be few and far between in the future, issuance by financial institutions is continuing apace. Just on A$3.2 billion of subordinated and hybrid notes have been issued to retail investors so far in 2013, and more are thought to be on the way.That said, the two large hybrid note issues from Westpac and National Australia Bank have so far given the impression of tapping all available investor demand. The bonds only moved to trade at face value last week, after trading at below face value since listing.Just how strong investor appetite is for more hybrid note issuance will likely be tested in the next week or so. Both Suncorp Group and Macquarie Group are expected to start marketing new issues to replace hybrid issues that are callable in June and are not Basel III compliant.Suncorp has A$740 million of notes outstanding and Macquarie has A$600 million. The Macquarie notes pay a fixed coupon of 11.095 per cent, which will be sorely missed by holders.The question for investors now is: what sort of coupon will be paid on the new note issues? Or, more precisely, what will the credit spread be?Both issuers will have to offer premiums to the 320 bps credit spreads paid by Westpac and NAB on their recent issues but presumably something less than the 465 bps offered by Suncorp on its A$560 million CPS issue completed last September. The range described here suggests a credit margin in the order of 380 bps to 400 bps may be appropriate to generate sufficient investor demand.Also, the Macquarie issue may be the more interesting of the two as it is unlikely to offer franking credits. This will appeal to a different class of investors who wish to receive the full cash value of the coupon upfront, rather than having to wait up to 18 months for a franking credit refund from the Tax Office.