What documentation should Washington buyers and sellers keep for private precious-metals sales?

1. Why paperwork matters now: the tax and business rules that drive documentation

Washington’s repeal of the longstanding exemption means gross income from sales of precious metal bullion and monetized bullion to end consumers is taxable under the Retailing B&O classification and subject to retail sales tax collection, so sellers need records showing whether tax was charged, why an exemption applied, and that any collected tax was remitted ^{[1] [2] [3] [4]}.

2. What every sales receipt should include: the minimum transactional record

Every private sale should generate a signed, dated receipt or invoice that records item descriptions (bullion vs. monetized coin), weight and fineness/purity, unit price and total consideration, sales tax charged (or notation of exemption), transaction date, and buyer and seller names and contact information—fields repeatedly emphasized in Washington guidance and industry advisories as necessary to determine taxability and to comply with retailing B&O reporting ^{[1] [2] [3] [4]}.

3. Proof for exemptions and reseller use: certificates and statements to collect

If a buyer claims exemption—such as a reseller certificate or a signed statement that coins are being purchased for manufacture into jewelry—the seller should obtain a completed Washington Reseller Certificate or a written, signed, dated statement as required historically under state guidance and industry practice, because Washington guidance and third-party dealer instructions treat these documents as the evidentiary basis for excluding a sale from tax ^{[5] [6]}.

4. Anti‑money‑laundering and identity records for dealers and frequent sellers

Federal rules for dealers in precious metals require written AML programs and, in practice, entail keeping identity and transaction records for business dealers; therefore private sellers who operate as dealers or make frequent sales should retain buyer identification, payment method records, and any suspicious-activity documentation consistent with 31 CFR part 1027 obligations ^[7]. The publicly available sources establish the AML duty for dealers but do not prescribe exact private‑sale thresholds—this analysis cannot state those thresholds beyond what the federal rule covers ^[7].

5. Certificates of authenticity, assays and provenance for value and dispute resolution

Certificates of authenticity, assay reports, mint documentation for monetized coins, and provenance records help establish the item’s characterization (bullion vs. numismatic) and therefore its correct tax treatment and market value; industry guides and dealer FAQs advise preserving such documentation because sales tax and B&O outcomes depend on whether the metal is valued for content or collectible attributes ^{[2] [8] [9]}.

6. Tax collection and remittance proofs: bookkeeping for sellers

Sellers who collect sales tax must keep records proving collection and remittance—tax returns, payment confirmations, and related bookkeeping entries—because Washington’s change makes bullion transactions look like other taxable retail sales and B&O gross receipts ^{[1] [3]}. Third‑party analyses and dealer advisories recommend tracking transactions separately when items can have mixed uses so correct tax rates and reporting can be applied ^[3].

7. Gaps in the public reporting and practical advice on retention

The sourced materials make clear what needs documenting but do not specify uniform state retention periods or detailed private‑sale thresholds for AML-style recordkeeping; therefore sellers should default to conservative practices—retain sales records, certificates, ID, and tax remittance proof for several years—and consult an accountant or Washington DOR for firm retention schedules and compliance audits ^{[1] [2] [7]}.