ONSIM
FAQ's
FAQs
Frequently Asked Questions
With all revolutionary technology there will always be lots of questions. The section below covers the most frequently asked, but please contact us if there is anything else you would like to know.
What is ONSIM?
ONSIM is a new type of highly advanced mobile network, designed to enhance your mobile experience with advanced features integrated natively into your mobile.
What number will be displayed when I make a call?
You can choose to display either your landline or mobile number when making calls, or even a shared 'office' number across multiple SIMs.
What is the coverage like?
In the UK our network covers more than 99% of the UK population and 90% of the landmass and it's powered by the UK's leading network, winner of the overall performance category for RootMetrics' tests 9 years running. When our users travel to other countries we will sometimes change the network to give access to local services and remove roaming restrictions/charges.
Is the service reliable?
Yes - thousands of UK businesses choose ONSIM as their business mobile network for this reason. It's also far more reliable than an APP.
Is this VoIP?
No, ONSIM uses traditional GSM/4G mobile networks for calls, ensuring higher reliability and call quality compared to VoIP/SIP/Apps.
Do I need to install any apps?
No, ONSIM SIMs allow you to use your mobile as normal without any additional apps.
What’s the difference between ONSIM and services such as BT One Phone Office?
BT’s service is VoIP-based, requiring an app or IP phone, while ONSIM uses traditional GSM/4G networks.
What’s the difference between ONSIM and Vodafone One Net?
Vodafone One Net is similar to ONSIM but locks you into Vodafone's network and is more expensive.
What’s the difference between ONSIM and Virtual Landlines?
Virtual landlines forward calls to a mobile number but do not allow outbound calls from the landline number, unlike ONSIM.
What’s the difference between ONSIM and other mobile networks?
ONSIM is designed specifically for businesses, offering a wide range of features to simplify and streamline communication.
Can I use our SIMs outside the UK?
Yes, but they are limited to the Home Zone (UK, EU, USA) by default to prevent unexpected charges. Roaming in other zones can be requested.
Can I have more than one landline number on the SIM?
Yes, you can have multiple landline or mobile numbers per SIM.
Can I send & receive SMS from the landline number?
No, SMS is sent from your underlying mobile number to ensure delivery.
Do you provide Auto Attendant or IVR services?
Yes, we offer IVR setup for ONSIM systems. Contact support for details.
Can I divert my number?
Yes, you can set up diverts to off-platform numbers via the portal.
What other features are included?
A list of features is available on the website. Contact support for specific requirements.
How do I get a mobile handset?
Contact the sales team for a hardware quote or purchase a handset from a third party.
Can I connect ONSIM to my current phone system?
It depends on your system and provider. Contact the sales team for integration details.
Can I have the same number on a desk phone & SIM?
Yes, we offer a twinned service allowing the same number on both mobile and office phone.
Do you offer mobile call & SMS recording?
Yes, we offer solutions for mobile call and SMS recording for business needs.
Do you offer more data or data bolt-ons?
Contact the sales team for larger data packages or shared data options.
Can I choose my new landline number?
Yes, you can choose from over 650 UK landline dial codes.
What landline area codes can you provide?
We offer all 650 UK landline dial codes.
Can I move my existing landline number over to Onsim?
Yes, we can port landline numbers from your existing provider.
When I choose my number when I order my SIM is that number guaranteed?
No. Please do not, under any circumstances advertise your new number until it's configured and you have tested it is working. ONSIM are not liable for any print costs or any other costs you incur as a result of prematurely advertising your number before you have tested it.
How long will it take for the SIM to arrive?
SIMs are dispatched via Royal Mail 1st Class, taking 3-5 working days.
What do I do when I receive my SIM?
Follow the instructions to activate your SIM. Guides are available in the help centre.
How long will it take for my new SIM to activate?
Activation can take up to 24 hours.
Do I need to use an unlocked handset?
Yes, your handset must be unlocked to use the Onsim service.
Does it work in any mobile?
No. Whilst the SIM's will work in most handsets on 2G in the UK, we would strongly advise that the service is used only with officially supported VoLTE devices. Please speak to support@onsim.uk if you have any questions.
Do I need a specific sized SIM?
No, our physical SIM's are compatible with Standard, Nano and Micro devices.
How much does it cost?
We offer a range of plans. Contact sales for volume pricing.
Is this a contract or pay as you go?
We offer 1 month pay monthly contracts, but not pay as you go.
When will I be billed?
Charges are taken up-front for 1 month, prior to the activation of your service. Then automatically on the anniversary of your first payment. For larger accounts we may align the billing day to the 1st of every month.
How will I be billed?
Billing is via saved Debit or Credit card. Direct debit is available for accounts over £50/month.
Do you require a credit check?
No but we reserve the right to perform a credit check to unlock certain features (such as roaming) or at our sole digression.
Can I upgrade my package in the future?
Yes, you can upgrade at any time.
What happens when I run out of minutes/data/SMS?
Depending on your configuration it can either block the service or charge for out of bundle usage at the published out-of-bundle rate.
How do I cancel the service?
You can request cancellation on the my.onsim.uk dashboard or by opening a support ticket. Refer to terms and conditions for details.
What if I want to cancel my service? Can I move my number elsewhere?
Yes, you can port your number to another provider. Keep your service active until the port is complete.
I have a problem, how do I get support?
Raise a support ticket via the online portal or email support@onsim.uk.
How do I raise a support ticket?
Raise a support ticket via the online portal or email support@onsim.uk.
When can I expect a reply?
Support tickets are usually replied to within 1 working hour.
How do I report a fault?
Raise a support ticket with call example details by emailing our support team (support@onsim.uk)
Do you offer phone support?
Yes but you will always need to raise a support ticket in the first instance.
Is ONSIM a legitimate telecoms company?
Yes. ONSIM LTD is a registered UK company (Company Number 08429703) operating since 2013. We provide telecoms services including landline numbers, mobile SIMs, and virtual landline services for business users.
Are you regulated by Ofcom?
Yes. ONSIM operates under Ofcom’s General Conditions of Entitlement, which apply to all UK communications providers. These include rules for contracts, number porting, emergency service access, CLI presentation, fair treatment, and more.
Do you need an Ofcom licence to operate?
No specific licence is required. Most telecom service providers operate under the General Authorisation Regime rather than holding physical licences, as long as they comply with Ofcom’s General Conditions.
Why does ONSIM not appear on Ofcom’s Electronic Communications Code register?
That register only lists operators who install physical telecoms infrastructure such as masts, poles, ducts or fibre. ONSIM does not install such infrastructure, so we are not required to appear on the register.
Can I call the emergency services (999/112) using ONSIM?
Yes. ONSIM SIMs support full access to 999/112. Both mobile and landline calling information is provided to the emergency services (PSAP) for accurate caller identification and routing.
Can I port my number to or from ONSIM?
Yes. ONSIM fully complies with Ofcom’s number portability rules. You can port mobile (PAC) or landline numbers into ONSIM, and you can port numbers out at any time without obstruction.
Are you part of an Alternative Dispute Resolution (ADR) scheme?
Yes. ONSIM is registered with Ombudsman Services: Communications, offering independent dispute resolution for unresolved complaints after 8 weeks.
Do you follow UK data protection laws?
Yes. ONSIM complies with UK GDPR, the Data Protection Act 2018, and the Telecommunications (Security) Act 2021 where applicable, ensuring secure handling of customer and call data.
How can I verify ONSIM’s details myself?
You can independently verify ONSIM LTD on the UK’s Companies House register under company number 08429703. You may also review our ADR registration, VAT number (GB163518900), and customer reviews on Trust Pilot.