SPID Number Explained: What It Is and Where to Find Yours

What a SPID number actually is

SPID stands for Supply Point Identifier. It’s the unique reference assigned to every business water supply point in the open market. Think of it as the permanent address of your water connection — the meter itself can be replaced, your retailer can change, your wholesaler stays fixed, but the SPID remains the same.

SPIDs are issued and managed centrally by MOSL — Market Operator Services Limited — which runs the English non-household water market. In Scotland the equivalent role is performed by CMA (Central Market Agency). Every premises with a non-domestic water supply has at least one SPID. Some sites have two: one for clean water in (potable supply) and one for sewerage out.

What a SPID looks like

A UK water SPID is typically a 13-digit number, usually written with hyphens for readability — for example 1234-5678-9012-3 or as a continuous string.

The format encodes information about the wholesaler region, the supply type (water vs sewerage), and a unique site reference. You don’t need to decode it manually — the format is for systems, not humans — but if you ever see “WSC” or “SSC” in your bill literature, that’s a Wholesale Supply Code or Sewerage Supply Code, which is closely related to your SPID.

Why your SPID matters

Four scenarios where you’ll need your SPID:

1. Getting a quote. Any broker or retailer pricing your business water needs your SPID to look up your supply point in the central market and pull historical consumption data. Without it, they’re guessing.
2. Switching retailer. The switch process registers your new retailer against your SPID in the MOSL central system. The wholesaler keeps supplying water exactly as before; only the billing relationship changes.
3. Raising a billing dispute. If a charge doesn’t match your meter readings or your consents, your SPID is the reference your retailer uses to pull the meter data, trade effluent consent, and rebate history from the central database.
4. A change of occupier or tenancy. When you take over a premises with an existing water supply, the outgoing occupier’s account is closed against the SPID and you open a new one against the same SPID. Get this wrong and you can be liable for the previous occupier’s outstanding balance.

Where to find your SPID

Three places, in order of how fast you’ll find it:

1. On your water bill. Almost every business water bill in the UK now prints the SPID near the top, usually labelled “SPID”, “Supply Point ID”, or “Supply Point Reference”. On some retailers it’s near the meter readings section.
2. From your retailer. Call your retailer’s business team and ask. They have it on file and can confirm in minutes.
3. Via the MOSL Customer Lookup tool. If you have neither a bill nor a contactable retailer, MOSL operates a customer lookup service that can return SPIDs based on postcode and address. Brokers use this regularly when onboarding new customers.

SPID vs MPRN vs MPAN — how they compare

If you have multiple utilities at the same premises, each will have its own separate identifier. They are not interchangeable. A water SPID does not help anyone find your gas MPRN or your electricity MPAN, and vice versa.

SPIDs when you move premises

A change of occupier (CoT) at an existing premises is handled by closing the previous account against the existing SPID and opening a new account against the same SPID with you as the responsible billpayer. The SPID does not change. Two things to do on day one of taking over:

• Take a meter reading and photograph the meter (with serial number visible). This is your liability boundary — anything before this reading belongs to the previous occupier.
• Contact the existing retailer in writing, attach the meter reading and photograph, and tell them you’re the new occupier from a specific date. They’ll close the previous account and open yours.

You can switch retailer at any point — including immediately after taking over a premises. There’s no requirement to stay with the inherited retailer.

What if I can’t find my SPID?

If you’ve inherited a premises with no recent bills, no contactable retailer, and the previous occupier has gone — that happens — give us the postcode and address and we’ll run a MOSL lookup and identify the SPID for you within a working day. Free as part of any quote we provide.

Working with Clearsight on business water

We pull SPIDs as the first step on every water enquiry. Then we audit your existing bills line by line, identify any rebate eligibility, and source competitive retailer quotes across the full market. No upfront fees.

Get a no-obligation business water quote in 60 seconds.

Related guides: Business water pillar, How to switch your business water supplier, Business water Letter of Authority, What is an MPRN (gas equivalent)?.