STAC code: switching without keeping your number

What is a STAC code?

A STAC is a Service Termination Authorisation Code. It is the counterpart to the PAC: where a PAC moves your number to a new network, a STAC tells the old network to close the service because you are moving without the number. Your new provider gives you a new number on a new SIM, and the STAC makes sure the old line stops at the right time.

Ofcom says texting for a STAC means the switch is done for you without paying notice period charges or paying twice for your old and new contracts. EE Business describes the STAC in similar terms: it switches off your current SIM and stops you being charged by two providers, without the hassle of talking to your current provider.

If you want to keep the number, you need a PAC instead: see our guide to the PAC code. The bigger picture is on our hub about how to keep your number.

How to get a STAC code

The routes mirror those for a PAC:

• One number on the account: text STAC to 75075 from that number, or ask by phone or on the provider's website. Ofcom says the reply to a text must arrive within one minute.
• More than one number on the account: Ofcom says you need to ask by phone or on the provider's website. O2 Business, for example, uses My O2 Business or your account manager for 2 to 24 numbers.
• Large moves: arrange them with your current provider or account manager; O2 Business has a "switch more than 24 numbers" option in My O2 Business.

The text service is free. Ofcom says a STAC is valid for 30 days, and your provider must send information about any early termination charge with it. If you only want to check your contract position before deciding, Ofcom, EE Business and O2 Business all describe texting INFO to 85075, which gives you that information without requesting a code.

STAC vs PAC: which should you use?

In practice, a business switching network often uses both. Staff phone numbers that customers ring move with a PAC. Data-only SIMs in tablets, routers and vehicles usually have numbers nobody dials, so a STAC is the simpler choice: see our guide to the business data only SIM. Old lines for people who have left are another common STAC case, though check first that nothing important (two-factor codes, supplier accounts, customer records) still points at the number.

Using your STAC to switch

1. Decide which lines are leaving without their numbers and note them separately from the lines that need a PAC.
2. Request the STAC from your current provider: STAC to 75075 for a single number, or online or by phone for several.
3. Order the new SIM or eSIM on your new business SIM only plan. The new provider issues a new number.
4. Give the STAC to the new provider within 30 days. EE Business, O2 Business and Vodafone Business all describe taking a STAC when you join.
5. Start using the new SIM. The old service ends when the new one starts, so the old provider should stop billing at that point.
6. Update records: email signatures, websites, two-factor authentication and any systems that held the old number.

STAC codes on each network

The text routes (STAC to 75075) work the same way whichever network you are leaving. The networks also publish their own notes.

EE Business

EE Business says you can text STAC to 75075 to get a STAC if you want to leave and take a new number, and that the rest of the process is the same as for a PAC. When you join EE Business with a STAC, it explains that putting the new SIM into a phone triggers a request to your old provider to stop the service, so give EE Business the STAC before you insert the new SIM.

Three Business

Three Business's switching help says you can either bring your existing number with a PAC or switch to a Three Business number. If you take a new number, Ofcom's process is to request a STAC from the network you are leaving and give it to the new provider.

O2 Business

For an account with one number, O2 Business says you can text STAC to 75075, ask in My O2 Business, or ask by phone. Where there is more than one number on the account, text requests are not available: use My O2 Business or your O2 Business account manager for 2 to 24 numbers, and the "switch more than 24 numbers" option for larger moves. O2 Business also notes that once you have redeemed a STAC with a new provider, you cannot then request a PAC for that number, because you have given it up.

Vodafone Business

Vodafone Business asks for a STAC from the provider you are leaving when you want a new number on joining. It says the code is valid for 30 days, and that businesses with 10 or more employees should go through their account manager or enter the code in Vodafone Business's Corporate Online portal (VCO).

Think before you give up a number

A STAC is final. Once the STAC has been used and the old service has ended, getting that number back is difficult or impossible, as O2 Business's own guidance on redeemed STACs makes clear. Before you use one, check:

• Is the number on anything public? Websites, adverts, vans, directories and business cards keep bringing calls long after a line closes.
• Is it used for security codes? Banking, payroll, cloud services and supplier portals often send sign-in codes by text.
• Do customers have it saved? A departing salesperson's number may be the one customers know. Moving it with a PAC to a colleague's new SIM can keep that business.

If in doubt, a PAC keeps your options open: you can move the number now and retire it later on your own terms. For number records when staff join and leave, see our fleet SIM cards guide.

How we help

When you move to a new network through us, we can help you sort each line into PAC or STAC, make sure nothing important is attached to the numbers you are giving up, and have the new SIMs or eSIMs ready for switch day. We supply business SIM only plans on EE Business and Three Business, and we can also supply O2 Business and Vodafone Business. Plans and terms are confirmed at quote.

Contact us with a list of the lines you want to move and we will suggest the cleanest way to do it.