Work out how you actually call before you shop around

Most people overpay because they buy a tariff designed for someone else. Before you compare anything, spend a fortnight noting down the shape of your international calling. Are you ringing a mobile in Poland for twenty minutes twice a week, or a landline in France for two hours every Sunday? Do you call one person or five? Do you ring from home, from the office, or on the train?

That pattern determines everything. A heavy weekly caller needs a bundled international add-on. Someone who rings abroad three times a year needs nothing more than a sensible pay-as-you-go rate and a spending cap. Write the numbers down — minutes per month, countries, mobile or landline, time of day — and you will immediately be able to spot which deals are relevant and which are noise.

Choose a tariff that matches that pattern

UK networks sell international calling in three broad shapes, and it pays to know which one you are buying.

• Inclusive international minutes. Some plans bundle a set number of minutes to a list of countries, usually landlines only. Perfect if your calling is regular and predictable, but check whether mobiles are included — they often are not.
• International add-ons. Bolt-ons that give you a few hundred minutes to a chosen country for a flat monthly fee. Usually the best value for one or two regular destinations.
• Pay-as-you-go international rates. Flexible but expensive per minute. Fine as a fallback, painful as a habit.

The trap is the "unlimited" plan that only covers landlines. If your friend in Spain only ever uses a mobile, you will be billed at the out-of-bundle rate for every single call. Check the small print for the words landlines only, and ask what the per-minute rate is to a mobile in that country if you exceed the bundle.

Lean on internet calling — but understand its limits

Voice calls over your home broadband or mobile data are, for most people, the single biggest saving available. A half-hour catch-up that would cost several pounds on a standard international rate costs nothing beyond the data, and you can usually see each other while you talk.

The catch is that "free" depends on a decent connection at both ends. A friend on a patchy rural connection in Italy will drop the call repeatedly, and you will both end up frustrated. Two practical habits help: agree in advance to fall back to a normal phone call if the connection fails, and keep a small allowance on your account so you are never stuck.

If you are calling from mobile data abroad, remember that EU roaming rules let you use your UK allowance in EU countries under fair-use conditions, but the rules have changed since Brexit and some operators now apply small surcharges. Check your operator's current roaming terms before you travel, not after.

Time your calls around time zones and off-peak windows

Timing is the cheapest trick in the book and almost nobody uses it properly. Most of continental Europe sits one hour ahead of the UK, and much of Eastern Europe is two hours ahead. That means a call at 8pm your time is 9pm or 10pm for your friend — late, but reasonable. A call at 6pm your time is far more welcome.

Many international rates also fall outside standard business hours. Evening and weekend calls are frequently charged at a lower rate, sometimes dramatically so. If your tariff has peak and off-peak pricing, shifting a regular Sunday afternoon call to a weekday evening can cut the cost substantially. If you are calling further afield, a quick check of the time difference before you dial avoids both wasted calls and 3am wake-ups.

Be clever about numbers, landlines and local access

A few simple workarounds shave off real money over a year.

• Ring the landline when it is practical. Landline rates to Europe are usually far cheaper than mobile rates, so if your friend has a home line and you are making a long call, ask them to ring you back on it.
• Use a virtual local number. Some services give you a number in the country you are calling, so your friend dials a domestic number and neither of you pays international rates.
• Group the call. One planned call with three friends around a table beats three separate calls of the same length.
• Keep calls focused. A twenty-minute call every week is usually cheaper and more satisfying than a two-hour marathon once a month.

Watch the bill and adjust as you go

Set a monthly spending cap with your provider so a long call cannot run away with your budget. Then check your bill for two or three months and look at the international section specifically: which numbers are costing the most, and at what time of day? Patterns appear quickly.

If one destination is consistently eating your money, that is your signal to move it into a bundle or shift it onto an internet call. If your calling has dropped off, downgrade the add-on rather than paying for minutes you never use. Reviewing this twice a year takes ten minutes and usually saves far more than the effort suggests.