Fake Dip Tests and Tank Storage Receipts — Verifying Oil Storage Documents

What is a dip test in oil storage?

In oil storage, a dip test is a manual measurement of what a tank holds. An inspector lowers a gauge tape with a weight, or bob, from a fixed reference point to find the oil level and any free water underneath. The American Petroleum Institute (API) sets out the procedure in Chapter 3.1A of its Manual of Petroleum Measurement Standards (MPMS), in an edition dating from August 2013 ^[1]. The Energy Institute's HM 4 (fourth edition, October 2022) covers manual level measurement in shore tanks and ships' cargo tanks ^[2]. ISO 4512 specifies the equipment, and was last confirmed by ISO in 2021 ^[3].

A level is not yet a quantity. Inspectors also take temperatures (MPMS Chapter 7), convert the level into a volume using the tank's calibration (Chapter 2) and correct it to standard conditions (Chapter 12) ^[1]. Samples are drawn under ASTM D4057, also published as MPMS Chapter 8.1 ^[1,4]. ASTM notes that a spot sample represents only one point in a tank ^[4].

Gauging and sampling are parts of a quantity and quality (Q&Q) inspection. SGS, for example, offers measurement ashore and on tankers, sampling, laboratory analysis and inspectors' reports for letters of credit, following API MPMS and Energy Institute HM guidelines ^[5].

Who orders and pays for a real tank inspection?

The buyer and seller order the inspection. Take BP's 2020 pipeline and tank provisions for the Americas. The parties jointly agree a licensed independent inspector and share all measurement costs equally. The party that holds the storage agreement with the terminal arranges the inspector's access. The inspector sends its reports to both parties, which use them for invoicing ^[6].

The terminal plays a separate role. Under the 2023 general conditions of VOTOB, the Dutch tank storage association, a storage company is not obliged to inspect goods for its client. Unless there is counter-evidence, its own tank soundings are binding, and the client may attend measurements in person or through a representative ^[7].

Nothing in these arrangements involves paying a third party for permission to dip a tank. The Rotterdam anti-fraud taskforce says paid "Authorization to Verify" and "Dip Test Authorization" requests are often used in fake deals ^[8]. The wider fee tactics are covered in our guide to oil trading scam red flags.

What genuine storage documents look like

Genuine storage paperwork comes from the terminal and goes to its client, the company holding the storage agreement or tank lease. Under VOTOB terms, a terminal owes information about stored goods only to its client, the client's legal representative or the holder of a store warrant, and may demand proof from anyone claiming to be entitled ^[7]. Typical documents include:

• Storage agreement. The contract between terminal and depositor, which BP's terms rely on for inspector access ^[6].
• Stock statements. Germany's stockholding agency EBV, in its July 2026 framework storage agreement, requires a stock report for each month-end by the 10th calendar day of the next month, plus an annual stocktake. Quantities are stated in kilograms and litres at 15°C under ISO 91 ^[9].
• Title transfer confirmations. In an in-tank sale, title passes under the terminal's standard operating procedures ^[6]. VOTOB terms require the client to notify the terminal of any transfer in writing and the new owner to accept the storage terms in writing. The terminal may refuse to recognise a transfer while its claims on the seller are unpaid ^[7].
• Store warrants. VOTOB defines these as documents signed by or for the storage company and bearing a serial number. They are issued only after the terminal has stored and measured the goods, at the client's request and the terminal's discretion ^[7].
• Injection and inspection reports. The taskforce says a genuine offer should come with an official Q&Q report from an inspection company working in the port, such as SGS or Intertek, and an injection report from the storage company ^[8].

The label on a seller's paper matters less than its issuer. A "tank storage receipt" (TSR) or "holding certificate" that the terminal did not issue, and will not confirm to you, proves nothing about stock or title.

How fake dip tests, TSRs and injection reports are used in scams

Most forged storage papers serve one purpose: to make a buyer pay before any oil changes hands. In one pattern described to FERM, the seller says the product must move to other tanks, and a "friend" offers space for three to five days, backed by websites, invoices and forged papers ^[10]. Late in 2025 an English oil trader prepaid for storage in Rotterdam. The documents proved forged, the oil did not exist and he lost almost $1.5 million, Dutch broadcaster NOS reported ^[11].

Fraudsters borrow real names. The storage company Standic told NOS that its name and its terminal manager's details appeared in forged documents, although it stores no petroleum products at all ^[11]. The Port of Rotterdam Authority says tank trucks have even arrived at terminals to collect products that do not exist ^[12].

Rotterdam's "Barrel" case shows that a real tank and a real inspector's name are not enough. Between March 2021 and July 2022, seven staged samplings took place at Shell's Pernis and Europoort sites without the permission of Shell or SGS. A sampling company then produced false reports suggesting large volumes of crude were for sale, used to back offers of 2 million barrels ^[13]. Prosecutors said the defendants posed as authorised inspectors in company clothing and under false names, and met buyers' questions with aggression and a video ^[14]. Footage from 31 May 2021 showed a man in safety gear, identified as an SGS employee, opening a tank valve and filling three bottles ^[15].

On 13 March 2026 Rotterdam District Court convicted the sampling firm's owner and the reports' drafter of forgery over nine false reports, which carried forged signatures. A Shell employee and an SGS employee were convicted as accessories. The main defendants were cleared of attempted fraud; all four received community service and suspended prison terms ^[13]. Cotecna warns that forged inspection certificates can cause "financial losses paying for cargo that does not exist" ^[16].

How to verify an inspection report or storage document

Verify with the issuer, using contact details you find yourself rather than those printed on the document.

1. Check that the issuer exists where it claims. The taskforce points to the Port of Rotterdam Authority's listing of companies and terminals, and keeps a blacklist and a whitelist of websites ^[8].
2. SGS. To verify an SGS report, use the company's online form, which it describes as "a free service to verify SGS-branded documents". Single documents go as PDFs and several as a ZIP file, up to 20MB ^[17].
3. Saybolt. Core Laboratories' TRAKK page validates Saybolt documents that carry the TRAKK logo; other Saybolt documents go through a separate request ^[18].
4. Cotecna. E-dox certificates can be checked by uploading them to Cotecna's website. Printed certificates must be originals with Cotecna's 2017 terms on the back, a serial number bottom left, a hologram top right and a seal visible under UV light ^[16].
5. Other inspectors. Where there is no online tool, ask the inspector's local office whether it issued the report, for whom, and whether the figures match its file.
6. The terminal. Because a terminal owes information only to its client ^[7], ask the seller to instruct the terminal in writing to confirm stock, title and any transfer directly to you. Then call the terminal on a number from its own website.
7. Your own inspection. Agree an independent inspector jointly, with access arranged by the storage-agreement holder ^[6], working to API MPMS or EI HM methods ^[5].

Red flags checklist

• A fee for a "dip test authorisation", an "Authorization to Verify" or short-term storage before you hold title ^[8,10]
• No Q&Q report from a recognised inspector, or no injection report from the storage company ^[8]
• Reports from a sampling firm you cannot check independently; in the Barrel case they came from a company owned by one of the defendants ^[13]
• A report the named inspector will not confirm through its official channel, or a printed certificate without its security features ^[16,17,18]
• A "TSR" or store warrant without a terminal serial number, or one the terminal will not confirm to you ^[7]
• Quantities quoted only in barrels, although a Rotterdam trader told FERM the port works in tonnes or cubic metres ^[10]
• A named terminal that does not handle the product offered ^[11]
• Videos, phone explanations and aggression in place of verifiable data ^[14]
• A few bottles drawn from a valve presented as proof of a whole tank's contents ^[4,15]

Alupetra checks inspection and storage documents with their issuers as part of its KYC and due diligence work from its Istanbul, London and Dubai offices.