Could you suggest a good and affordable VOIP provider for making mobile phone calls in the UK? I am specifically looking for one that allows changing the CallerID without authentication and has a reliable DTMF function.

In addition, it would be great if you could recommend providers who offer plans with around 25 minutes of talk time.

In the UK, we are a telecommunications service provider that connects directly to numerous local and international operators through the Direct Range from UK Regulator Ofcom. We are capable of handling over 500 simultaneous calls at any given time, with peaks exceeding 1000.

When it comes to Caller ID, it is crucial to work with wholesale operators who ensure that you sign a CLI agreement, committing not to manipulate or fake the caller ID. Violating this agreement can result in account suspension, involvement of the authorities, and potential financial penalties.

One example of a provider is voip.ms, although I personally caution against relying solely on cheap providers who prioritize price over quality. VoIP offers much more than just empty calls and minutes; it provides scalability, flexibility, and reliability.

Unfortunately, the market is inundated with companies that engage in prohibited activities, flooding the industry with unreliable and inexpensive communications.

From a serious provider's perspective, managing the Caller ID without exclusive rights poses significant risks in terms of violations and fines. Trustworthy providers typically have restrictions in place to prevent unauthorized manipulation of the CLI.

You mentioned the need for 25 simultaneous calls. To better assist you, could you please provide more details on the number of minutes required per month? For instance, if you need around 15 simultaneous calls, estimating approximately 150,000 minutes per month may be feasible.

It's worth noting that reputable providers often charge for transponder usage, such as voice bandwidth. This is worth considering, especially for startups and small entrepreneurs who may not be aware of the actual amount of voice bandwidth they require.

There are a few key factors to consider, especially regarding your specific needs: the ability to change Caller ID without authentication and having a reliable DTMF (Dual-Tone Multi-Frequency) function. Additionally, it sounds like you're looking for plans that offer around 25 minutes of talk time.

One provider you might consider is VoIPstudio. They have a straightforward pricing model and generally offer plans suitable for casual users. Their service is known for good sound quality and reliability, which is crucial for mobile calls. VoIPstudio allows for Caller ID manipulation, and while it's essential to check specifics around authentication, they typically offer flexibility in this regard. Their plans can easily accommodate around 25 minutes of talk time, depending on the specific package you choose.

Another option to explore is 8x8. They provide a variety of pricing plans, and you can often find one that includes around 25 minutes of talk time. Moreover, 8x8 is recognized for its robust DTMF functionality, which is vital when interacting with automated systems over the phone. Changing Caller ID may also be simpler compared to some other providers, but it's always best to confirm current capabilities directly with their support.

If you're looking for something even more budget-friendly, consider SIPgate. This provider has a pay-as-you-go model, which can be beneficial if you anticipate making less frequent calls. They support Caller ID changes, but, again, check their latest policies as these features can sometimes vary. Their DTMF reliability is generally good, but it's worth testing before committing to ensure it meets your needs.

Lastly, ensure that whichever provider you choose offers a user-friendly app for mobile use. This can significantly enhance your experience, especially if you're making many calls on the go. Always read recent customer reviews and support feedback to ensure the service is up to your standards.
VoIPstudio, 8x8, and SIPgate are three comprehensive options that should meet your criteria for affordable VoIP services in the UK. As always, I recommend contacting these providers directly to confirm their capabilities regarding Caller ID management and DTMF reliability.