Key Takeaways
- Grading-hold lists mute sellers until the PSA/BGS cert last-four on the listing matches the slab photo.
- Union mute with STOP, vacation, and authenticity holds — one radio, not four overlapping nags.
- Keep buyer login OTP off the trust-and-safety tablet that dumps slab reminders.
- Service pricing is devices plus SMS send volume. You bring the Android phone and operator credit.
- Free is 1 device, 300 SMS lifetime, 300 contacts. Developer is 25,000 SMS per year.
- Honor STOP even when a slab comes off hold. A re-list is still promotional unless they opted in again.
Summary
Marketplace lists in scenario 1559 are sports-card grading holds: mute seller outreach until the PSA/BGS cert last-four on the listing matches the slab photo. Unlike mute union, KYC, dispute, locker-ready, seller ban, payout holds, holiday cutoff, listing hold, review-request, inbound dock, IP takedown, serial-returner, VAT hold, vacation mode, MAP floor, gray-import, late-ship strike, age-gated, authenticity serial-photo, handmade-policy, brand-takedown, hazmat UN, live-animal, used-auto VIN, or Rx/OTC, this list is a cert match, not a pharmacy aisle.
Service pricing is devices plus SMS send volume. You bring the Android phone and operator SMS credit. Free is 1 device, 300 SMS lifetime, 300 contacts. Developer is 25,000 SMS per year. Starter, Professional, and Business list Unlimited SMS as platform send volume; devices and airtime stay metered.
A full grading cert in SMS is a catalog key you leaked. Send last-four. Keep the cert on the listing. Mute until the slab photo matches.
Key takeaways
- Grading-hold lists mute sellers until the PSA/BGS cert last-four on the listing matches the slab photo.
- Union mute with STOP, vacation, and authenticity holds — one radio, not four overlapping nags.
- Keep buyer login OTP off the trust-and-safety tablet that dumps slab reminders.
- Service pricing is devices plus SMS send volume. You bring the Android phone and operator credit.
- Free is 1 device, 300 SMS lifetime, 300 contacts. Developer is 25,000 SMS per year.
- Honor STOP even when a slab comes off hold. A re-list is still promotional unless they opted in again.
Related reading
Start from contacts, lists, and segments, compare device and SMS volume pricing, open SMS auto-reply and STOP keywords, and review CTIA messaging principles.
Context
Trust desks land here after a hold-only send nagged a seller whose slab still failed OCR, or after a full cert leaked in a “helpful” template. Buyer OTP cannot share that tablet.
Core scenario guidance
Union mute before radio. Template: cert last-four + portal. Drop full certs. Honor STOP. Isolate OTP.
| Lane | SMS body | Fail closed |
|---|---|---|
| Grading hold | Cert last-four | Full PSA/BGS number |
| Photo mismatch | Mute | Nag anyway |
| STOP | Suppress re-list nags | Keep buyer OTP |
| Buyer OTP | Separate device | Same SIM as slab burst |
Canary a staff listing after OS updates. MCP wraps REST. Developer Center owns fields.
Cost and ownership
Devices + volume + operator airtime on every hold-only send. Developer is 25,000 SMS per year. Free (1 / 300 / 300) proves pairing, not a collectibles desk.
Operations
Daily last-seen, battery, mute-union diffs. After a cert-OCR change, one staff canary. On-call before unattended auction cutoffs.
Security and compliance
Cert numbers identify inventory. Encrypt at rest. Never log full certs from SMS. Verify TLS on every callback.
Decision guide
Ship when mute union, last-four templates, STOP, and OTP isolation exist. Delay if a mismatch can still nag. If zero phone ops is mandatory, evaluate CPaaS for that slice.
Checklist
- Mute until cert match.
- No full cert in SMS.
- Honor STOP.
- OTP isolated.
- Spare paired.
Next steps
Return to Android SMS gateway server guide, compare device and SMS volume pricing, open device setup, and confirm APIs in SMS API documentation.
Deep dive: production hardening
Mute union before radio is non-negotiable. A hold-only send still spends airtime. Battery exemptions dominate overnight auction queues.
Deep dive: scaling and failure modes
Scale is listings times hold days, not a blast of the catalog. Never claim unlimited free cloud SMS credits with no device or volume meter.
Deep dive: integration discipline
Developer Center owns live API parameters. Persist listing id + cert last-four. MCP is a REST wrapper. If zero phone ops is mandatory, evaluate CPaaS. You bring the Android phone and operator credit.
Related product pages
Jump to the live product docs for this topic—not another long-form article.
- contacts, lists, and segmentsAudience hygiene
- bulk SMS from Excel and CSVSpreadsheet campaigns
- bulk SMS with consent best practicesHigh-volume outreach
- SMS API documentationLive endpoint reference
