Exchequer recorded debts on split willow sticks

From around 1100, the English crown needed to record enormous numbers of tax and loan obligations across a kingdom with no reliable postal system, no paper industry to speak of, and widespread illiteracy that made written contracts hard to verify or dispute in court. A written record on parchment could be forged, altered, or simply disputed by an illiterate debtor who couldn't check what it said; the Exchequer needed proof that didn't depend on trusting a document's wording at all.

The obvious fix within available technology, a duplicate written record kept by each party, still relied on both copies matching and neither side being able to alter theirs undetected, exactly the vulnerability a purely textual record carried in the first place.

The Exchequer notched the amount of a debt into a stick of willow, then split the stick lengthwise into two unequal pieces: the longer 'stock' went to the creditor, the shorter 'foil' to the debtor. Because willow's natural grain is unique to each piece of wood, the two halves would fit back together, and their internal grain patterns would match, only with each other, making a forged or altered match essentially impossible to fabricate.

Notched the debt into a willow stick, split it so unique grain made halves match only each other, and made the creditor's half negotiable.

The split willow halves fit only each other, so forgery was physically impossible.

Verification required no literacy or third party, only matching the two halves.

The negotiable stock half turned a debt record into a tradable financial instrument.

The system relied on wood's unique grain, not institutional enforcement, so it lasted centuries.

When trust in documents fails, encode the record in a physical property that makes forgery detectable by construction, and consider making the record transferable.

By the decade 1437-47, tallies of assignment accounted for roughly 64 percent of English tax receipts, making a notched stick of wood the crown's primary medium of public finance for centuries, alongside actual coin. The system ran essentially unchanged from around 1100 until an 1826 act finally mandated paper-based accounting instead, though implementation dragged on for years.