Direct answer. A useful peptide document request identifies the legal supplier, exact SKU and pack, quotation or lot stage, destination and the question the file must answer. Keep the specification, contract, invoice and packing record on the same product and commercial basis.
How do I request a COA from a peptide supplier?
Send a document request that can be matched to a quotation or lot. A general request for “the COA” is harder to answer because product identity, batch stage and analytical scope may differ.
| Material | Exact SKU, grade, strength, pack and current specification version |
| Reference | Quotation number, lot number or the stage at which a lot will be assigned |
| Buyer context | Company, destination market and intended business project |
| Document question | Which parameter, method or transaction record needs to be reviewed |
| Evidence scope | Whether a representative file is sufficient or lot-specific evidence is required |
The sequence that prevents mismatches
Start with the written product specification. The quotation should repeat the same SKU, grade, strength and pack. The contract should capture the agreed commercial terms. The invoice should match the seller, buyer and product basis. The packing list and shipment record should allow the delivered goods to be compared with the order.
COA, TDS and SDS are not one document
A COA reports tested results for a material or lot. A TDS explains material information. An SDS communicates hazard and handling information. Review the scope and issue date of each one, and do not assume that a general document applies to the lot being purchased.
Invoice and beneficiary checks
Before payment, compare the legal seller on the quotation, sales contract and invoice with the bank beneficiary. If a payment instruction changes, verify it through an independent known contact channel. Never rely on an email attachment alone.
| Record | What it should answer | What to compare |
|---|---|---|
| Sales contract | What has the seller and buyer agreed? | Legal parties, SKU, quantity, pack, price basis, delivery terms and payment terms |
| Commercial invoice | What is payable and by whom? | Seller, buyer, product description, quantity, currency, amount and stated payment route |
| Packing list | What is included in the shipment? | SKU, pack, quantity, labels, cartons and shipment references |
Export transactions are supported with a commercial invoice. For an eligible domestic transaction, the applicable China VAT invoice and tax basis must be confirmed with finance for the actual seller, product and order; this website does not issue an invoice automatically.
Certificate of analysis or certificate of testing?
Document names and formats vary. A COA commonly reports results against a product or lot specification, while a certificate of testing may list tests performed without using the same structure. Read the actual product identity, lot reference, methods, results, limits and issue information rather than relying on the title alone.
Keep versions. Save the approved quotation and proof version, not just the final invoice. If product, quantity or packaging changes, request updated written documents.