Founding audit window open No upfront fee while slots are open Send one invoice page. Recovery memo back in 48 hours.
Procurement as a service, on contingency

I take over your vendor
negotiations and lower your bills.

You send invoices from two spend categories. I find what you are overpaying, renegotiate it with the vendors, and recover what was billed above contract. You pay a share of what you actually save.

Run by a former Global Procurement Manager at HP - the buyer's side of these exact contracts.

Start with two categories
Plan in 5 business days Send invoices from two categories to start.
No upfront fee 25% of what you actually save. Nothing saved, nothing owed.
Cheaper than the hire No headcount, no software, no lock-in.

Someone is buying. Nobody owns what it costs.

Finance asks whether the numbers tie. Operations asks whether the work got done. Almost nobody asks whether the rate was right, whether the contract still applies, or whether this renewal should have gone up at all. So it quietly does, month after month, until someone finally sits down with the vendor.

Where the money goes

Not one big mistake. A system of small charges nobody renegotiates.

It sits in the boring, repeated line items no one re-checks and no one renegotiates - where your contract terms and everyday exceptions quietly decide your margin.

01

Suppliers, logistics and fulfilment

Unit prices that drifted from the agreed sheet, volume tiers that never switched on, payment terms, plus pick-pack, storage, parcel, freight, packaging and returns.

02

Software and payments

Auto-renewals nobody caught, unused licences, tools bought twice, and payment processing rates left at the default.

03

Agencies and contractors

Media fees charged as a percentage of ad spend that grew while the work did not, retainers running on two-year-old scopes, staff augmentation, professional services and recruiting fees.

How it works

Two categories in. A savings plan out in 5 business days.

1

Send two categories

Invoices from the two categories that hurt most, plus the contracts if you have them. No call and no system access needed to start.

2

Get the plan in 5 days

Every line checked against the contract and the market: what was overbilled and is recoverable, what should be renegotiated, the target terms, and what it is worth over twelve months.

3

You approve, I negotiate

You sign off on the strategy and tell me which vendors are off limits. Then I run the conversations end to end and hand you the new terms in writing.

Founding client offer

No upfront fee. You pay a share of what you save.

One mechanism, nothing else: 25% of the savings and recoveries that actually land in your first twelve months. If I find nothing worth acting on, you owe nothing.

25% of realised savings, first 12 months
Start with two categories
  • No upfront fee, no retainer, no software to buy.
  • No system access needed for the first review.
  • NDA available before sensitive files are shared.
  • You approve the strategy before I contact a single vendor, and you name any vendor I must not touch.
  • Past overbilling I recover is included, not billed separately.
  • If there is nothing worth acting on, you get a clean no-go and owe nothing.
  • Best fit: companies with real vendor spend and nobody whose job it is to manage it.
Founder-led review

Maciej Marek

I spent six years inside corporate finance and procurement - I started in accounts payable at Akamai, moved onto its procurement team, then sourcing at GEP Worldwide and Global Procurement Manager at HP. I negotiated the supplier contracts and reconciled what those vendors billed against what was actually agreed. For the past four years I've also worked alongside DTC and CPG brands on their operations, Amazon channel, and compliance. MarginSentry is where those two worlds meet: a procurement insider who reads your invoices, then sits in the vendor conversation on your side of the table. Not a dashboard and not a report. The negotiation itself.

Maciej Marek
Ex-Akamai · GEP · HP 6 yrs procurement + sourcing Invoice + contract reconciliation Verify on LinkedIn ->
FAQ

Questions finance and ops usually ask first.

What does this cost?
No upfront fee and no retainer. I keep 25% of what actually lands in your first twelve months: recovered overbilling plus the savings from renegotiated rates, counted only once they are real. If there is nothing worth acting on, you owe nothing.
What do you need from us to start?
Invoices from the two categories you think hurt most, ideally the last twelve months, plus the contracts or order forms if you have them. Redact whatever you want on the first pass. No call and no access to your systems.
How quickly will we know if there is money in it?
Five business days from receiving the files. You get what was overbilled and is recoverable, what should be renegotiated, the target terms, and what it is worth over twelve months. If the answer is not much, you get that in writing too.
Will this damage our vendor relationships?
No, and you keep control of that. You approve the strategy before I contact anyone, and you can rule any vendor out of scope entirely. Most of this is routine billing correction and a normal renewal conversation, not a fight.
How do you handle our invoice data?
An NDA is available before any sensitive file is shared. We take only the minimum needed to find the signal, you can redact names and identifiers on the first pass, and we never need login access to your systems.
Do you just flag it, or do you actually do the work?
I do the work. I draft the claim, run the vendor conversations, and negotiate the new terms. You approve the strategy up front and sign whatever gets agreed. That is the point of paying on results.
Which categories do you cover?
Suppliers and product costs, logistics and fulfilment (3PL, parcel, freight, packaging), agencies and contractors, professional services, software and subscriptions, and payment processing. In short, the money that leaves the business without anyone owning the rate it leaves at.
Do you also find new suppliers, or only renegotiate the ones we have?
Both, and the split of work matters. I run the process. Writing the requirement down with you, finding and approaching candidates, running the RFQ, putting every quote into one comparable table, and negotiating price and terms. You keep the parts only you can own, which are the specification, the quality decision and the final choice. A competitive RFQ also creates its own benchmark, so nobody has to guess what the market rate should be.
How fast does each type of work pay off?
Recovering what was billed above contract is the fastest, usually weeks. Renegotiating an existing agreement is next, and it lands at the renewal or sooner if there is leverage. Sourcing a new supplier is the slowest, four to eight weeks for the process plus the switch, so it is worth starting only where the size of the category justifies the wait.
Who on our team should handle this?
Usually the CFO, Controller, COO or the founder. The strongest fit is the person stuck between "ops says this is normal" and "finance keeps paying it."
What if you find nothing?
Then you owe nothing, and you have it documented that those categories are clean. I do not turn a no-go into a retainer pitch.

Two categories in. A savings plan out in 5 business days.

Leave your details. I reply with a secure way to send the invoices, then the plan lands within five business days. No call, no system access, and no fee unless you save.