Ask first, post later
Start with a question, not a parcel. Send a photo on WhatsApp or call, and you will get a straight answer on what testing tier suits your item and what the report will cover. None of it commits you to posting anything.
This is a UK-wide postal testing service. There is no shop to visit and no counter. Wherever you live, the process is the same: ask first, then decide.
A hallmark
A UK hallmark is a set of legally-controlled marks applied to a precious metal item by one of the four UK Assay Offices: London (Goldsmiths'), Birmingham, Sheffield or Edinburgh. The Hallmarking Act 1973 reserves these marks — anyone in trade selling a precious-metal item above the minimum weight without one commits an offence under the Act.
The mark guarantees that the item meets a legal minimum standard of purity (e.g. 375 ppt for 9ct gold). It does not say what the actual content is; the actual content could be 375 ppt or it could be 390 ppt — the mark is a floor, not a measurement.
A hallmark is also a record. It identifies the Assay Office that tested the item, the year it was marked, and (where present) the maker / sponsor. Antique hallmarks are themselves valuable historical records.
An acid test
A traditional acid test involves filing a small mark into the item to reveal the metal underneath, then applying a calibrated nitric acid to that mark and observing the reaction. The reaction colour and rate indicate the carat range of the gold. Cheaper and faster than XRF, used widely in pawnshops, jewellers and gold-buying counters before XRF became affordable.
It has three limits. It is destructive (the filed mark is permanent), it is operator-dependent (the result varies with technique and acid age), and it is an approximation (it puts the item into a carat range, not a parts-per-thousand reading).
On most modern Niton-equipped buyers, acid tests are kept for special cases — heavily plated suspects where XRF is being defeated by plating thickness — rather than as the primary method.
An XRF test
XRF spectrometry is non-destructive, fast, and reads the actual elemental composition of the metal — every element, in parts per thousand. Where the hallmark gives a legal floor and the acid test gives a carat range, XRF gives the measured composition itself.
It does have limits worth knowing. It reads only the surface and a short depth into the metal, so heavy plating can occasionally mimic solid metal on a single scan. The SOP defence is a multi-point scan trace — readings at face, edge and corners — which exposes plating signatures cleanly.
It also does not read inside a closed bezel-set stone, and it does not read non-metallic materials. For stones, the in-house gem service is the right tool.
When each method is right
| Question | Hallmark | Acid test | XRF |
|---|---|---|---|
| Does this meet a legal standard? | Yes, that is what it does. | Roughly. | Yes, and shows by how much. |
| What is the actual fine gold content? | No — guarantees a floor only. | No — gives a carat range. | Yes, to parts per thousand. |
| Is this plated or solid? | The hallmark may indicate, if present and trusted. | Yes, after the filing. | Yes, with multi-point scan. |
| Will my item be marked or damaged? | No — applied by the Assay Office. | Yes — small filed area. | No — non-destructive. |
| What other metals are in the alloy? | No. | No. | Yes — every element shown. |
| Is it valid in court / probate / insurance? | Yes — legal mark. | Not on its own. | Yes, as an expert composition record. |
Insurance and tracking
Your parcel is insured up to £2,500 via Royal Mail Special Delivery. For higher cover we can arrange a tracked courier before you post, with the cover level agreed in writing first.
The label is Royal Mail Special Delivery Guaranteed by 1pm next working day, with full tracking and signature on receipt. The tracking link is emailed to you the moment the label is issued.
What you get back, and when
Your item is returned by Royal Mail Special Delivery on the same working day the report is issued. Return postage and insurance are included in the testing fee — there is no separate return charge.
If, for any reason, an item cannot be tested (badly damaged surface, non-metallic core, equipment misalignment), we tell you straight, refund the testing fee, and return the item the same day.
The independence pledge
You can use this testing service without ever wanting to sell. Many customers do. We test. You decide. There is no obligation to ask for an offer, no commission paid to the team for converting a test customer into a sale, and no upsell embedded in the report itself.
If you ask, at the end, whether the item is something we would buy, we will tell you straight. If you do not ask, the report stands on its own.
What this report is, and what it is not
The report identifies the elemental composition of an item to the accuracy of the analyser. It does not replace a UK hallmark, an Assay Office fire assay, or a written valuation from a qualified valuer for insurance reinstatement purposes. We say so in plain English on the front page of every report.
If a report leaves any doubt, we will tell you what the next step would be — typically a UK Assay Office fire assay (destructive but definitive) for high-value disputes, or a written insurance valuation from a qualified independent valuer for reinstatement cover.
Why sellers choose GoldPaid
GoldPaid is a small, owner-run UK business built on one promise: show the working. Every item is XRF-assayed and weighed on calibrated scales, every offer is itemised in writing, postage is free and insured both ways, and there is never a countdown or a hard sell. If something is worth more to a specialist than to us, we say so.
Common questions
Is an acid test enough to know whether to sell my piece?
For a binary "solid or not" question, an acid test will get you most of the way there but it leaves a filed mark on the item. The plating check at £25 is the same binary question, non-destructively, with a written report.
Can XRF and a hallmark disagree?
Sometimes — and when they do, the XRF reading is usually correct. The most common cause is replaced parts (a chain hallmarked 9ct with a 14ct repaired clasp) or solder joints diluting the average. The multi-point scan trace usually finds the disagreement.
Is fire assay better than XRF?
For a definitive, court-grade reading on a single sample, yes. Fire assay is destructive — the item is melted down — and is the gold standard the UK Assay Offices use for disputes. For a non-destructive, written composition record across multiple items, XRF is the right tool. The report identifies the fire assay route as the next step on contested high-value items.
Why do you not offer acid testing?
Because the customer is paying for an honest, non-destructive report. Filing a mark into an inherited piece to get a less precise result than XRF would be the wrong service for the customer.