Avoid.
Avoid.
We were inherited as customers when ASC acquired Connecting Britain's hosted phone platform. Leaving cost us weeks of chasing, a £972 invoice we don't accept is lawfully due, eleven days without our main business line during our busiest period, and a legal threat on a contract they'd told us five times didn't exist.
In August 2026 ASC wrote that no customer contracts had been assigned in the acquisition, so it held no agreement with us, and gave two options: sign new terms or take 30 days' notice and port away. We chose to port.
Thirty days is not a realistic window to select a provider, complete a Letter of Authority and port 54 numbers. We started the day the letter arrived; the earliest port date was one day past the deadline.
Early emails were reassuring. On 24 August: no charges if the port completed within the notice period. On 28 August: once a port request was confirmed, numbers and services would stay active and free. Neither held.
Once the port was submitted, ASC invoiced £15 + VAT per number, £972 in total, payable within 48 hours or services would be suspended. The basis changed between emails: first our Connecting Britain terms, later withdrawn in writing, then an upstream supplier cost. Ofcom's General Conditions require porting without direct charge to the end user.
We disputed it. Our calling was barred and our main number went dead. We asked for two numbers to be forwarded to a temporary line, offering to pay: refused until the invoice was paid. We asked for evidence of the upstream cost: one £15 line item, quantity one, dated before our port request existed.
ASC then wrote it would not process the exports unless paid upfront, and ten minutes later that it had never suggested blocking the port. The same day, having told us on 21 and 24 August, 7 September and twice on 14 September that no contract existed, their legal team sent a 7-day letter asserting a "legally binding contract has been executed". It also thanked us for being a charity. We are not a charity.
Connecting Britain Ltd, the company we actually contracted with, entered liquidation eleven days after ASC's letter. Both records are on Companies House. ASC inherited its customers, so Connecting Britain's reviews are worth reading alongside these.
If you're in the same position: don't pay to leave. Ofcom's rules don't allow a direct charge for porting, and the carrier confirmed to our new provider that a losing reseller cannot hold numbers hostage over unpaid bills. File an Ofcom complaint and keep the reference; there's an industry Port Override Request process, run by the Office of the Telecommunications Adjudicator, for losing providers who suspend service or refuse to release numbers. Only your new provider can start it, and they'll need your reference. And ask your new provider to escalate with the underlying carrier directly. That's what moved things for us.
The numbers ported on the scheduled date, through the carrier, without ASC's cooperation being needed. We did not pay the invoice.
We would not recommend ASC to any business that depends on its phone numbers. Get a signed contract with explicit porting terms before committing anything, or look elsewhere.