Talking to suppliers about compatibility groups
Why suppliers use their own numbering, how to map it to yours, and what to ask for so reorders never go wrong.
3 min read
Tempered glass isn't manufactured per phone model. It's manufactured per shape, and one shape serves many models. That's why a supplier's catalogue has far fewer entries than there are phones — and why their numbering never quite matches anyone else's.
Understanding that mismatch makes reordering reliable.
Why groups exist at all
A factory tooling up for a new protector is cutting a specific outline: a diagonal, a corner radius, cutout positions, a curvature profile. Any phone matching that outline can use the part. One tool therefore serves every model whose front face matches.
In our data the largest group covers 154 models with a single part. The smallest covers two. That distribution is normal — popular panel designs get reused across whole product lines and across brands, because several manufacturers buy panels from the same suppliers.
Everyone's numbering is different
Your supplier has a code. Their supplier has a different code. A second supplier selling the identical shape has a third. None of them are standardised, and none are published.
This is worth accepting rather than fighting. The practical approach is to maintain a mapping: your reference code on one side, each supplier's code on the other.
That's what the supplier_code field on our part data is for. Once you know that a part group corresponds to a particular supplier's code, record it, and reorders become unambiguous.
What to ask a supplier
"What's your part number for this shape?" — not "what fits a Vivo Y21". You want the code, because the code survives when the model name is forgotten.
"What else does this number fit?" — a good supplier will tell you, and their list is a useful cross-check against your own. Discrepancies are worth investigating; they usually mean one of you has a variant wrong.
"Is this full glue or edge glue, and is it 2.5D or 3D?" — these are orthogonal to the shape. The same group number can be sold in several adhesive and curvature types.
"Do you distinguish the 4G and 5G versions of this model?" — if they hesitate, treat that model as ambiguous until you've verified it yourself.
When your data and theirs disagree
It happens. A supplier says their part fits a model your reference doesn't list, or vice versa.
Neither source is automatically right. Supplier catalogues contain optimistic entries; reference data contains transcription errors. The way to settle it is a physical dry-fit, once, and then record the answer.
If you find a genuine discrepancy in this site's data, it's worth correcting at the source rather than remembering it — knowledge that lives only in someone's head walks out of the shop when they do.
Buying for stock rather than per job
Once you know which groups cover the models you actually see, stocking becomes straightforward. A handful of high-coverage groups will handle a large share of walk-ins.
Look at the part pages here sorted by model count: the biggest groups cover the phones most likely to come through the door. Stocking depth in three or four of those beats stocking breadth across twenty.
The long tail is genuinely a tail — worth ordering per job rather than holding.
Keep the mapping somewhere shared
A supplier code written on a sticky note above one bench is not a record. Put it somewhere the whole shop can read, ideally next to the part group it corresponds to. The cost of not doing this only becomes visible on the day the person who knew is away.