Every contractor has lived through one of two purchase order disasters. In the first, a buyer raises a £14,000 order against a supplier nobody vetted, at a rate nobody checked, and the first the commercial team hears of it is on the cost report a month later. In the second, every order — a £40 box of fixings included — has to wait for a director who is on site three days a week, so procurement grinds to a halt and buyers start raising orders "informally" just to keep the job moving.
Both come from the same mistake: treating purchase order sign-off as a single switch that is either on or off. The answer is not more approval or less approval. It is approval that matches the size of the commitment — so the small stuff flows and the big stuff gets the eyes it deserves.
Why a single gate always fails
A flat rule — "everything needs the MD's signature" — feels safe, but it trains people to route around it. When approval is slow and indiscriminate, buyers learn to split orders, raise them after the fact, or phone the supplier and sort the paperwork later. The control exists on paper and protects nothing in practice.
The opposite — no sign-off at all — is how committed cost quietly parts ways with the budget you won the job on. An order raised at the wrong rate, against the wrong supplier, or over a line that is already fully committed is exactly the kind of leak that never announces itself. By the time it surfaces in reconciliation, the money is gone.
What you actually want is a ladder: trivial orders pass straight through, mid-value orders need a manager, and the numbers that can move a job's margin need a director. That way the people who should be looking at large commitments are looking at them, and nobody is asked to rubber-stamp a £40 order.
A ladder, not a gate
This is exactly how Vyntworks handles it. In Settings → Quotes → Default Authoriser you build a company-wide ladder of PO authorisation tiers — value thresholds, each with one or more authorisers, where any one of them can approve. A purchase order is routed automatically to the highest threshold its value clears.
Set £5,000+ to need a manager and £10,000+ to need a director, and the routing takes care of itself: a £6,000 order goes to the manager, a £12,000 order goes to the director, and a £300 order sails through against the normal default authoriser without troubling anyone. List two authorisers on a tier and either can clear the queue, so one person being on annual leave never stalls procurement. The whole ladder has a single Enabled toggle, and the thresholds use your own company currency.
The effect is that the friction lands where the risk is. Buyers stop feeling punished for routine purchasing, and the orders that genuinely deserve a second look actually get one — because the approver is not drowning in trivial ones.
One project, one exception
No two jobs carry the same risk, so a fixed company ladder is rarely the whole story. A flagship project with a nervous client, or a job running on thin margin, might warrant tighter sign-off on one particular band without changing the rules everywhere else.
Vyntworks handles that with project exceptions: override a single band on specific projects while every other band still follows the company ladder. Add one exception row per project and band — pick the project, choose the threshold to override, and name the authoriser. Route the £5,000 band on two named projects to a different approver, and the £10,000-to-director rule still applies on those jobs because you never touched it. Any band you do not override simply inherits the company default, so you adjust one tier without rebuilding the ladder.
Where the sign-off actually bites
Routing only matters if the order genuinely stops until it is cleared. A purchase order sits at PendingAuth until an authoriser approves it; only then does it move to Authorised and push to your connected accounting software. The committed cost does not go live, and nothing reaches the supplier, until the right person has said yes. Subcontract orders work the same way — one that would push a line or the project over budget moves to Authorising and emails the approver, who opens an approval page and chooses Approve or Decline, recording a reason if they decline.
Because the order is anchored to the lines it commits, the approver is not signing a number in a vacuum. They can see it against the budget it draws down — which is the difference between approving a commitment and approving a guess.
Sign-off should be a seatbelt, not a handbrake. If your approvals are either too loose to protect margin or too slow to live with, book a walkthrough and we will set the tiers up on one of your own projects so you can watch routine orders flow and the big ones land on the right desk.