How to beat mobile bill shock

No one wants to meet a four-digit phone bill. Whether it's calls or data that sneak up on you, here are just a few ways to make sure you never have to find one in your future.

Your latest mobile phone bill has just come in, and it's an absolute heart stopper. By going only a few megabytes, calls and text messages over your cap allowance, your bill has somehow blown out to three or four digits. That fun holiday, house renovation or gadget that you had planned to spend your hard-earned money on has been relegated to a pipe dream. Make sure you never end up here again, or here for the first time, by keeping a few key checks in mind.

Check your bill carefully

Don't assume that everything on your bill is correct, as hiccups in the back-end system of each carrier can and frequently do result in unwarranted charges.

The difficulty is actually deciphering all of the different charges that appear on your bill. Make no mistake, mobile phone bills are purposefully designed to be as confusing as possible — so much so that each of the major carriers has a tutorial on their website that explains what each of the charges mean. Here's where you can find them: Telstra; Vodafone; Optus.

Obviously, you should call customer service and complain if you find any suspicious charges on your bill. Even if it all looks legit, however, it may be worth calling anyway. When it comes to bills that run into the hundreds or thousands, carriers have been known to show a bit of leniency and knock some money off the total if you plead ignorance, especially if it's a result of going over your data allowance.

If all else fails and you can't afford to pay your bill by the due date, ask customer service if you can pay it off in instalments. Doing this before the due date of the bill means your service won't get restricted while you're paying it off. Of course, to make sure you don't rack up another huge bill next month, read on.

Change your plan if necessary

If you're on an AU$50 cap and your bill is regularly over a hundred dollars, you should be changing your rate plan.

Cap allowances that offer hundreds of dollars worth of calls and hundreds of megabytes of data can lull you into a false sense of security; the problem is that once you use up that cap allowance and switch to paying for things on a per unit basis, the charges can rack up alarmingly quickly.

This is where it's worthwhile to look at your last three or four bills. If they're consistently well above your monthly cap amount, then it's time to move to a different plan. The good news is that there's no fee to do this — your carrier will only charge you if you move to a cheaper plan.

There are two ways to go about this. You could either move to a higher rate plan, which will give you more credit and data across the board, or you can add a data pack that only increases your data allowance. It really depends on your usage.

Adding a data pack before you actually go over your monthly allowance can save you hundreds of dollars in excess usage charges. Say you’re on Telstra's Every Day Connect AU$60 plan, which comes with 1GB of data. If you consume twice as much data that month, you would be slugged with AU$100 in excess usage charges (Telstra charges 10 cents per megabyte over your monthly allowance and calculates gigabytes as 1000 megabytes). If you had added a 1GB data pack on before you went over your limit (and these can be added and removed on a month-by-month basis), it would have cost AU$15 only.

As for knowing when you need to add on a data pack, see the next step.

The Optus MyPlan range is the only exception to the rule. There are no excess usage charges for these plans at all. Once you go over your monthly credit and/or data allowance, Optus will automatically bump you up to the next rate plan and then switch you back to your original plan as soon as the next billing cycle starts.

Monitor your data usage

There are several methods you can use to keep an eye on the data you use each month. It is now mandatory for all carriers to send usage alerts when you reach 50 per cent, 85 per cent and 100 per cent of your data, but since the system can be as much as 48 hours behind, you can often receive the usage alert well after you've used up your data allowance. The same problem exists when you log in to your online account page or use official carrier or third-party apps to check your account usage, as they're all using the same information.

Luckily, the latest mobile operating systems come with tools built-in to monitor your data usage in real time.

iOS has a built-in data tracker (found in Settings > Mobile) that adds up all of the data you've used and handily breaks it down by app so you can see which ones are the biggest data hogs. The only problem is that there's no way to get it to reset at the start of your billing cycle every month. One way around this is to set yourself a reminder in the Reminders app to hit the "Reset statistics" button at the bottom of the screen first thing in the morning on the first day of your billing period.

Android has a more sophisticated data-monitoring feature built-in that lets you specify the dates of your billing cycle and the amount of data you have each month. You can even force it to cut your mobile data off as soon as you reach your monthly threshold. Like iOS, it also breaks all of the data usage by app.

Limit your data usage

This one may seem a little obvious, but it's worth going over, especially when it comes to the finer points of tethering.

There are certain activities that use a lot more data than others, and you should switch to Wi-Fi as much as possible when you are video streaming (think YouTube, news sites and Facebook), music streaming, VoIP and video calls (such as Skype, Viber and FaceTime), large app downloads and uploading photos and videos.

A handful of apps can actually compress the amount of data that you use by routing everything through a special server. Onavo Extend, available for iOS and Android, is the best third-party app for this, letting you get up to five times more data out of your plan by compressing images, emails and web traffic (streaming media and VoIP are coming soon). One of the best features of Onavo Extend is that it actually tells you how much money and data you’ve saved every time you open the app. It also breaks down your monthly usage by app and session.

Opera Mini, available for all of the major mobile platforms, can compress web pages by up to 90 per cent, allowing for faster page loads and considerably less data usage. Chrome Beta for Android offers the same feature, although you’ll have to manually enable it — going to Settings > Advanced > Bandwidth Management > Reduce Data usage.

You should also be mindful of what you tether your mobile phone to. There are plenty of apps that automatically update whenever the device is connected to a Wi-Fi network, so a harmless request from a friend to tether to your mobile phone may result in you blowing out your monthly data allowance, and this applies for both desktop and mobile devices.

Dropbox on a smartphone, for example, will automatically upload all the latest photos and videos as soon as it's on a Wi-Fi connection. iOS devices can also backup to iCloud automatically and update apps in the background. Desktop computers can also be configured to automatically download the latest system updates whenever they’re connected to Wi-Fi, and these are frequently several hundred megabytes large.

Be smart about using your phone overseas

Global roaming charges, especially for mobile data, can easily cause your bill to hit four figures if you aren't careful. As soon as you turn your phone on overseas, everything becomes a lot more expensive — you're even charged to receive incoming calls and text messages from Australia, and data can cost up to AU$15 a megabyte.

Your best bet is taking your SIM card out of your phone and replacing it with a local SIM card. Airports are usually a good place to track down prepaid SIM cards for travellers. Of course, this option isn't available in every country, and there's also the chance your phone is locked to your carrier, in which case other SIM cards won't work.

It's worthwhile checking the options that your carrier offers for international travel, as they'll certainly be cheaper than paying the standard global roaming charges. Telstra offers a variety of international data packs starting at AU$29 for 100MB, and these are available in 50 countries, including Thailand, Singapore, New York and Dubai.

Optus has recently slashed the cost of its global roaming charges and has reduced the amount of geographical zones (which determine which pricing tariffs to apply) to two. It will also be introducing an AU$10 Optus Travel Pack that gives customers unlimited calls, texts and 30MB of data for use in the most common travel destinations.

Vodafone offers a good deal too, but you need to be on a specific plan to take advantage of it. The RED plans (starting at AU$65 a month for unlimited calls to Australia, unlimited texts internationally and 1.5GB of data) let you use your entire plan allowance in the US, the UK and New Zealand for only AU$5 extra a day.

Another option worth exploring is grabbing a global SIM card before you go overseas. These SIMs work in a variety of countries and offer affordable rates for calls and data. Woolworths has a special Global Roaming prepaid SIM card that works in more than 230 countries — the appeal of this approach is that you can't spend more than the amount you've topped the card up with. Globalgig offers cheap international "Jetsetter" plans starting at AU$19 per month for 1GB data that you can use in 11 countries, including Hong Kong, the USA, the UK and Ireland. Globalgig's plans aren't prepaid, but there are no lock-in contracts, either.