Successful mortgage lending is often said to require a system of registration, which records the ownership of, and any encumbrances on, a particular piece of real estate. Here we analyse how Sweden's Riksens Ständers Bank handled the uncertainties of the mortgage lending market c. 1680–1700, when there was no coherent system of property registration. The bank tried to make registration compulsory, but when influential groups opposed this move, the bank had to modify its lending practices. The study thus sheds light on the somewhat fraught initial stages of the shifts in the credit system, which from the latter half of the seventeenth century onwards, saw personal trust replaced by system trust, and private credit replaced by institutional credit.