For solicitors, accountants & consultants
A trusted UK landline number for your practice
Clients expect a 01 or 02 landline number from a professional services firm. A personal 07 reads as junior or unestablished. ONSIM puts your firm's landline number on the same mobile you already carry — no second handset, no VoIP, no app to install.
From £5/month + VAT. Live in minutes. Port your existing firm number in.
Why a landline number matters for professional services
Client trust starts before they call
For a first-time client looking for legal, accounting or financial advice, the number they're dialling does work. A 020 or 0161 reads as an established practice with a physical presence — even if you work mostly remote.
Keep your personal mobile private
Your firm number goes on letterheads, business cards, and Law Society / professional body listings. Your personal mobile stays out of client hands. Same phone — clean separation.
Compliance options when you need them
Mobile Call & SMS Recording and Compliance Recording add-ons available for regulated practices (financial services, legal, healthcare). Talk to sales for a tailored Enterprise quote.
Three tiers, pick what fits
Virtual Landline — £5/mo
Inbound calls divert to your existing mobile. Cheapest credible business landline. No SIM swap, no app, no setup fee.
Landline SIM — £10/user/mo
Outbound calls display the landline number. Hunt groups, voicemail, deskphone pairing included. Unlimited UK calls and SMS (fair use). Standard SIM or instant eSIM.
Enterprise — from £20/user/mo
Mobile call & SMS recording, compliance recording for regulated practices, shared/ wholesale data, international numbering. Sales-led, custom pricing.
Frequently Asked Questions
What solicitors, accountants and consultants most often ask before signing up.
Why do professional services need a landline number?
Clients — particularly older clients, regulated industries, and anyone instructing a solicitor or accountant for the first time — expect a 01/02 landline number. A 07 mobile alone reads as either a junior practitioner or an unestablished business. The landline number does work before you even pick up the call.
Is ONSIM appropriate for a regulated practice?
Yes for general client telephony. ONSIM also offers Mobile Call & SMS Recording and Mobile Compliance Recording as paid add-ons, which suit regulated businesses (financial services, legal, healthcare) that need recorded-line compliance. Speak to sales for a tailored quote: +44 333 880 4008 or quote.onsim.uk.
Can I keep my existing chambers' or firm's number?
Yes. ONSIM ports most UK landline numbers — typically 10-14 working days from receipt of the porting form. Port-in fee is covered. See the keep-your-landline-number guide. Many practices port a long-standing landline number off a copper PSTN line before the January 2027 switch-off using ONSIM as the destination.
Can multiple partners or fee-earners share the same landline number?
Yes. With Landline SIM and 2+ users you can set up hunt groups (one included on multi-user accounts) so calls to the firm number ring across multiple fee-earners simultaneously or in sequence. IVR menus and call queues are available as paid add-ons if you need menu-driven routing.
Can my clients reach me out of hours, on holiday, abroad?
Diverts can be set to voicemail, to another colleague, or to a different number based on time of day. With the Landline SIM, the SIM works in 39 Roam-Like-At-Home countries on UK allowances — your landline number stays reachable when you travel.
What's the cost?
Virtual Landline £5/month + VAT (inbound calls only). Landline SIM from £10/user/month + VAT (inbound + outbound landline caller ID, unlimited UK calls/SMS). Both are monthly rolling. Enterprise tier from £20/user/month for practices needing mobile call recording, compliance recording or international numbering.
A firm number that clients trust
7,500+ UK businesses use ONSIM, including solo practitioners and growing practices. Live in minutes. Port your existing firm number in.