AQL Inspection for Phone Importers
How AQL (Acceptable Quality Level) sampling works for phone and electronics inspections — sample sizes, defect classifications, and pass/fail thresholds.
AQL (Acceptable Quality Level) is a statistical sampling method that defines the maximum acceptable percentage of defective units in a lot. AQL 1.5 is the B2B standard for major defects in phone inspections. An AQL 1.5 inspection of a 500-unit shipment requires checking 80 phones; the lot passes if 3 or fewer major defects are found and zero critical defects are present.
What AQL Means in Practice
AQL (Acceptable Quality Level) is a statistical sampling standard defined in ISO 2859-1. It specifies the maximum percentage of defective units considered acceptable in a lot. Rather than inspecting every unit, inspectors check a statistically derived sample and accept or reject the entire shipment based on the result.
For phone importers, AQL inspection is the standard method for pre-shipment quality control. You define your AQL levels and defect criteria before the shipment, instruct a third-party inspection company accordingly, and receive a pass/fail report against your own thresholds.
AQL Levels Used in Phone Trade
Two AQL levels are applied simultaneously — one for major defects, one for minor defects.
| Defect Type | Typical AQL Level | What It Means |
|---|---|---|
| Critical defects | 0 (zero tolerance) | Any critical defect = automatic rejection |
| Major defects | AQL 2.5 | Up to 2.5% major defects accepted |
| Minor defects | AQL 4.0 | Up to 4.0% minor defects accepted |
AQL 2.5 for majors and 4.0 for minors is the standard starting point in the wholesale phone trade. Buyers sourcing premium refurbished stock or high-value models often tighten major defects to AQL 1.5.
Defect Classifications for Phones
Define these categories explicitly in your inspection brief. Vague criteria produce inconsistent results.
Critical defects — automatic lot rejection regardless of AQL:
- Unit does not power on
- IMEI blocked, blacklisted, or reported stolen
- Activation lock (iCloud/FRP) present and not cleared
- Counterfeit device
Major defects — counted against the AQL 2.5 threshold:
- Cracked or broken screen
- Broken or non-responsive touchscreen
- Camera, speaker, or microphone failure
- Battery not charging or capacity below stated grade
- Charging port failure
- Cosmetic damage exceeding grade specification (deep scratches, dents affecting structural integrity)
Minor defects — counted against the AQL 4.0 threshold:
- Missing or incorrect accessories (cable, box, SIM tool)
- Packaging damage that does not affect the device
- Light scratches within grade tolerance
- Incorrect label or documentation
Sample Size Tables
AQL sample sizes are drawn from ISO 2859-1 inspection level II (General Inspection Level II is the default for most trade inspections). The lot size determines which sample size code letter applies, which then gives the sample count.
| Lot Size (units) | Sample Size Code | Sample Size | AQL 2.5 Accept/Reject | AQL 4.0 Accept/Reject |
|---|---|---|---|---|
| 91–150 | F | 20 | 1 / 2 | 2 / 3 |
| 151–280 | G | 32 | 2 / 3 | 3 / 4 |
| 281–500 | H | 50 | 3 / 4 | 5 / 6 |
| 501–1,200 | J | 80 | 5 / 6 | 7 / 8 |
| 1,201–3,200 | K | 125 | 7 / 8 | 10 / 11 |
| 3,201–10,000 | L | 200 | 10 / 11 | 14 / 15 |
Accept/Reject columns show the maximum defects allowed (accept) and the number that triggers rejection. For a lot of 500 units inspected at AQL 2.5, the inspector checks 50 units — if 3 or fewer major defects are found the lot passes; 4 or more and it fails.
Free AQL Calculator Tools
You do not need to work through the ISO tables manually. Several free tools handle this:
- AQL-Calculator.com — straightforward web tool; input lot size, inspection level, and AQL values
- InTouch Quality’s AQL calculator — widely referenced in the sourcing industry
- QIMA’s AQL guide — includes downloadable reference tables
For recurring use, the ISO 2859-1 tables are reproducible in any spreadsheet.
Instructing a Third-Party Inspection Company
Send a written inspection brief that specifies:
- Lot size and expected SKUs
- Inspection level (General Level II unless you have a reason to deviate)
- AQL levels by defect category (e.g., Critical: 0, Major: AQL 2.5, Minor: AQL 4.0)
- Your defect definitions — do not rely on the inspector’s defaults
- Specific functional tests required (power cycle, IMEI check, touchscreen, cameras, cellular signal, battery %)
- Grade criteria with cosmetic examples if available
Reputable inspection companies (Bureau Veritas, SGS, QIMA, Asia Quality Focus, V-Trust) will map your brief directly to their checklists. If an inspection company asks you to skip the written brief, treat that as a red flag.
When a Lot Fails AQL
A failed inspection result gives you three options:
Reject and reship. The supplier bears cost of return and replacement under most trade agreements if the failure is documented. Get the rejection in writing with the inspector’s report attached before any further communication with the supplier.
100% sort at origin. The supplier (or a hired sorting team) inspects every unit, removes defective stock, and re-submits the remaining lot for re-inspection. This adds time and cost but preserves the relationship and salvages stock that is mostly good.
Renegotiate price. If the defect rate is borderline and you can absorb the remediation cost (screen replacements, accessory substitution), a price reduction may be acceptable. Calculate your landed cost including remediation before agreeing to any discount. Document the revised terms in writing.
Never accept a failed lot without a written resolution. An undocumented verbal agreement about a failed shipment is unenforceable.