09 numbers explained: 0908, 0909 and 098

09 numbers are the UK's premium rate range. A call to one costs two things added together: a service charge, set by the line you are ringing and printed next to the number, and an access charge, set by your own phone company. Ofcom reserves 0908, 0909 and 098 for adult services.

That is the short version. The longer one explains why the figure on the advert and the figure on the bill so often seem to belong to different calls, and what to check before you ring.

What are 09 numbers?

A number starting 09 tells you something before you have dialled the rest of it: this call costs more than an ordinary one, and part of what you pay goes to the service at the other end. That is what 'premium rate' means. The phone company carries the call, collects the money through your bill, and passes most of the service charge on to whoever runs the line.

The same two-part system covers a few cheaper neighbours. Numbers starting 084 and 087 are 'service numbers' with a much smaller charge, and 118 numbers are directory enquiries. Everything below applies to them too; the sums are simply smaller.

0908, 0909 and 098: the adult ranges

Within the 09 range, Ofcom sets aside particular blocks for particular kinds of service. 0908, 0909 and 098 are reserved for what the regulator calls sexual entertainment services. An adult chat line in the UK should be on one of those prefixes and nowhere else.

That is more useful than it sounds. You know what kind of line you are ringing before you ring it, and anyone who wants to bar those calls from a phone, a parent or an employer, say, can do so precisely without losing access to the weather line or the cinema booking number. If you are curious how the old 0898 numbers became today's 09 ranges, the history of UK chat lines tells the story.

How much do 09 numbers cost? Service charge plus access charge

Since 1 July 2015, the cost of calling any service number has been split in two.

• The service charge is set by the company you are calling. It has to be shown clearly next to the number wherever the number is advertised, in wording along the lines of 'Calls cost Xp per minute plus your phone company's access charge'.
• The access charge is set by your own phone company. It is a single per-minute figure that applies to every service number you ring on that tariff, and it appears in your network's price guide.

The first part is the same for everybody. The second depends entirely on your contract, and it is the one people forget. Mobile networks usually set it higher than a home landline does, which is covered in why 09 calls cost more from a mobile.

There is also a regulated ceiling on how high a service charge can go. A reputable line will sit well below it, and the rules on showing the price are there so that nobody has to guess.

How a minute gets counted

Two lines advertising the same rate can still produce different bills, because a minute isn't always a minute.

Per second

You pay for the time you were actually connected. Six minutes and ten seconds costs six minutes and ten seconds. It is the only method that lets you do the sum in your head while you talk.

Rounded up to the minute

Every minute you start is charged in full, so six minutes and ten seconds becomes seven. On a long call the difference barely registers; on a short one it can be a noticeable share of the total.

Connection fees and bundles

Some services add a fixed charge the moment you connect, or sell time in blocks. They are the hardest to compare, because the headline figure doesn't match any length of call you can picture.

Why a low rate isn't the same as a cheap call

A slow answer costs more than a slightly higher rate. It is plain arithmetic, and it is the part most comparison tables leave out.

Take two lines. The first costs a little less per minute but leaves you on hold for two minutes before anyone picks up. The second costs a little more and answers in about ten seconds. For ten minutes of actual conversation, the first bills you for twelve minutes and the second for just over ten. The 'cheaper' line has to be roughly 15% cheaper per minute simply to break even, and every extra minute of hold music moves the goalposts further.

The number that matters is the price of the conversation, not the price of the minute.

Our own rate, and how it is charged, is on our cheap phone sex page. As the rules require, it sits next to the number rather than in the small print.

The waiting problem

A premium rate call has three stages: connecting, waiting and talking. The talking is what you rang for. The waiting is where things go wrong, because a service that charges for waiting has every reason to make you wait. One that answers promptly has the opposite incentive, and that single sentence tells you most of what you need to know about a line.

Signs worth noticing:

• hold music that carries on long after the price announcement;
• menu after menu before you reach a person;
• repeated requests to 'hold for just a moment';
• a conversation that slows down for no reason, with long, unexplained pauses.

How premium rate calls show on your bill

The charge goes on your phone bill, or comes off your pay-as-you-go credit. There is no card to enter and no account to open, which is a large part of the appeal. The catch is timing: on a contract you only see the cost when the bill arrives, weeks later. The meter runs where you can't see it, so it pays to understand the counting before you ring, not after.

An itemised bill also lists the number you called. Worth bearing in mind if the bill is shared with anyone.

If you would rather not have 09 calls available on a line at all, or would like a limit on them, ask your phone company. Most can bar premium rate numbers, and some offer spending controls you can switch on and off. What happens on our own line once you are through, from choosing someone to hanging up, is laid out in how it works.

Three questions before you dial

What is the service charge, and where is it shown? What is your own network's access charge? Are you charged while you wait? A line that answers all three plainly is one whose cost you will know before the bill tells you.

Frequently asked questions

How much do 09 numbers cost?

There is no single figure, because every call to an 09 number has two parts: the service charge printed next to the number, and your own network's access charge. Add them together to get the real cost per minute, then multiply by the length of call you have in mind. Your network's price guide lists its access charge, usually under 'service numbers'.

Are 09 numbers included in my inclusive minutes?

Almost never. The minutes in a mobile or landline bundle generally cover ordinary UK numbers starting 01, 02, 03 and 07, and premium rate sits outside them. The whole cost of an 09 call lands on top of your monthly bill, or comes straight off your pay-as-you-go credit. If in doubt, your tariff's terms will say so in the section on non-geographic numbers.

Is a 0909 number a scam?

Not in itself. 0909 is one of the ranges Ofcom reserves for adult entertainment services, so a legitimate adult line is supposed to use it. What separates a decent service from a poor one is whether the price is shown clearly next to the number, whether someone answers promptly, and whether you are charged for long stretches of waiting.

How can I stop 09 numbers being called from my phone?

Ask your phone company to bar premium rate numbers. Most landline providers and mobile networks can do it, often through your online account, and some can bar only the adult ranges or add a spending control instead. It is worth doing on a family line, a work phone or any phone a child might use.

What should I do if a charge looks wrong?

Start with your phone company, which can tell you who operates the number and whether the call was connected for as long as the bill says. Keep a note of the date and time. The premium rate regulator, whose work now sits with Ofcom, has long offered a public number checker for tracing a service.