1 prefix · leasing company
BSIU container prefix: Blue Sky Intermodal
BSIU is registered to Blue Sky Intermodal, a container leasing company. Blue Sky Intermodal owns the box and does not carry it: track it with the shipping line named on your booking or bill of lading, because that line holds the record of where it is. The check digit is worked out below for this prefix.
Blue Sky Intermodal is a UK-managed lessor with a compact fleet placed mainly with Asian and European regional carriers.
Its single code appears rarely enough that shippers often meet it for the first time on a lease query.
4 letters + 7 digits, printed on the doors. It is on your bill of lading too.
The answer appears as you type. Nothing is sent anywhere.
The Blue Sky Intermodal prefix
| Prefix | A valid number | Check digit | Where the code comes from |
|---|---|---|---|
BSIU | BSIU 505923-0 | 0 | — |
Prefix register verified against two independent sources on 2026-08-03. The example numbers are computed to show the arithmetic. They are valid by construction, not numbers we saw on a box.
Data: BIC Container Prefix Register · ISO 6346:2022
BSIU: check digit, worked through
BSIU is registered to Blue Sky Intermodal. Take BSIU 505923-0: each of its first ten characters has a value and a weight, the products are added, and the remainder after dividing by 11 is the check digit — here 0.
| Character | Value | Weight | Product |
|---|---|---|---|
B | 12 | ×1 | 12 |
S | 30 | ×2 | 60 |
I | 19 | ×4 | 76 |
U | 32 | ×8 | 256 |
5 | 5 | ×16 | 80 |
0 | 0 | ×32 | 0 |
5 | 5 | ×64 | 320 |
9 | 9 | ×128 | 1152 |
2 | 2 | ×256 | 512 |
3 | 3 | ×512 | 1536 |
Sum 4004 → 4004 mod 11 = 0 → check digit 0 → BSIU 505923-0
Owner and operator: who tracks a Blue Sky Intermodal box
Blue Sky owns the steel; whichever line hired it holds the tracking record.
Can you see where the ship is?
Not from the container. A standard dry box has no power, no radio and no satellite receiver — it is a steel case with a number painted on it, and it reports nothing about itself. Every position you see against a Blue Sky Intermodal shipment was reported by something else: a terminal crane, a gate reader, or the ship.
A live map on a carrier’s tracking page is almost always plotting AIS, the transponder every large vessel broadcasts with its position, course and speed. That is genuinely useful at sea: it is a real position rather than a schedule, and an ETA recalculated from actual movement. It is also the ship’s position, not your box’s, and the two part company the moment the container is discharged.
On land the map goes quiet. Between the gate-out and the delivery there is no vessel to follow, and the road leg appears only as whatever events the terminal and the trucker report. A container sitting on a chassis in a yard shows the last position of a ship it left days ago. Only specialised IoT equipment reports its own location, and wherever that exists it is a paid product sold to the shipper, not something a tracking page gives away.
Frequently asked questions
Who owns the BSIU container prefix?
Blue Sky Intermodal does, a container leasing company — the BIC register lists BSIU under it, and the boxes sail in other lines' fleets.
How do I track a BSIU container?
Not with Blue Sky Intermodal — a BSIU box is leased, so the record of its journey is with the shipping line named on your booking confirmation or bill of lading. Open that line's tracker and paste the number there.
Is BSIU a shipping line prefix or a leasing prefix?
A leasing prefix — Blue Sky Intermodal owns the steel box while a shipping line operates it, which is why the owner and the tracker are different companies.
Is BSIU5059230 a valid container number?
Yes — BSIU 505923-0 passes the ISO 6346 check: the weighted sum for BSIU505923 leaves a remainder of 0 when divided by 11, which gives check digit 0. It is an example computed for this page, not a box we have seen.
One page, every owner code
Know whose box it is before you search
All 85 owner prefixes mapped to their line or leasing company, with the leased ones marked — so you can tell at a glance when to track with the line instead. Container dimensions are on page two.
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