Involved in the transformation of 5-formyl tetrahydromethanopterin (5-formyl-H(4)MPT) to methanofuran (MFR) and formate via the intermediate formylmethanofuran (formyl-MFR). Catalyzes the transfer of a formyl group from 5-formyl-H(4)MPT to MFR to produce tetrahydromethanopterin (H(4)MPT) and formyl-MFR, which is then hydrolyzed to formate and MFR. 5,6,7,8-tetrahydromethanopterin + H(+) + N-formylmethanofuran = methanofuran + N(5)-formyl-5,6,7,8-tetrahydromethanopterin Optimum pH is 7. One-carbon metabolism; formaldehyde degradation; formate from formaldehyde (H(4)MPT route): step 4/5. Homotetramer (By similarity). Octaheteromer. Part of the formyltransferase/hydrolase complex fhc; composed of FhcA, FhcB, FhcC and FhcD (PubMed:11532013, PubMed:12123819). Belongs to the FTR family.