Verifying Islamic MFIs is not enough. Most, if not all of them, only provide Islamic microfinance on a subset of their loans — not on all loans.
Therefore, above and beyond verifying Partners, you need to check on a loan by loan basis to see which ones are 0% interest.
A sample 0% loan is listed here. You can see under “Additional Information about this loan,” it mentions that “RI-Iraq charges 0% interest on this loan.”
Check your loans; don’t just assume. Alternatively, you can use this RSS feed, which automatically searches verified Islamic MFIs for 0% loans. (It’s also the orange icon in the right-hand sidebar.)
May Allah help our brothers and sisters in need, here and overseas (ameen).