A purchase requisition is an internal document: somebody in the business asking for permission to buy something, before any supplier has been contacted or any commitment made. It is easy to confuse with a purchase order, and the distinction matters because the two are approved by different people for different reasons at different moments, and getting the order of those moments wrong removes the control entirely.
What goes on one
The requester and their department, what is wanted and in what quantity, an estimated cost, the cost centre or budget it comes from, when it is needed, and why. A suggested supplier is optional and is often better left to purchasing, who may have an agreement in place. Keep the form short: a long requisition form is the most reliable way to make people stop raising them.
Who approves it and against what
Usually a budget holder, against a threshold set by value. The question being answered is whether the organisation should spend this money at all, which is a different question from whether the eventual invoice is correct. Confusing the two is why approval sometimes ends up happening only at the invoice stage, by which point the money is already committed.
What happens next
An approved requisition is turned into a purchase order by whoever handles buying, and the order goes to the supplier carrying its own number. The requisition does not disappear: it is the evidence of who asked and who agreed, and it should stay attached to the order and, later, to the invoice that matches it.
Questions people ask about purchase requisition
Is a purchase requisition legally binding?
No. It is internal. The commitment to a supplier is made by the purchase order or the contract, not by the request.
Who raises a requisition?
Whoever needs the goods or service, which is usually somebody outside finance. That is why the form has to be short and the process has to be quick.
Do small purchases need one?
Most organisations set a threshold below which a requisition is not required. Setting one deliberately is better than leaving people to guess, which produces inconsistent practice and awkward conversations later.