What is Royal Mail?

Royal Mail plc is the primary postal service in the United Kingdom. It provides postal delivery services to all 64 million inhabitants of the British Isles. They have a rich history, being credited with being the first to develop and put into practice the postage stamp.

Yeah, we're talking about those guys, people. They're kind of a big deal.

The Royal Mail address format is slightly different from the USPS format. In case you're looking for a crash course on how to address a letter to England, Scotland, Ireland, Wales etc., here it is in brief.

Name:               Cpt. Steven Rogers
Street address:     221B Baker Street
Town/village/city:  LONDON (all caps)
Postal code:        NW1 6XE

Bottom left-hand corner is where this one goes. Your return address would go on the backside, where the flap of the envelope is.

History of Royal Mail

Before we go any further, we need to brush up on our history, so we can understand a little more about how, what and why Royal Mail do the things they do. Today they may go by the name Royal Mail plc, but they've seen lots of changes over the years. So let's start at the beginning.

In 1516, Henry VIII first set up a guy to be called "Master of the Posts." This, logically, was the precursor to "Postmaster General."

Next highlight: the invention of the postage stamp. The first-ever postage stamp, "The Penny Black," came into use in the UK in 1837. A mere decade later and France's La Poste had adopted stamps as well. Back then, postage prices were pretty nebulous, and people most commonly had to pay for postage as they received it. Boy, would that be a nasty trick to play on someone. Everyone seemed, well, stuck on the idea of using something as a mark of prepayment. So in 1840, the Penny Black went into circulation and the postage stamps we know today began.

Like Deutsche Post, for the first few hundred years of its life, the British postal system was run and maintained by the state. But that all started to change in 2006: the market was opened to competition and ended a 350-year monopoly the British Empire had held over the postal market within its own borders. A few years and a few bits of legislation later, the British government tossed a bunch of Royal Mail corporate stock shares out onto the public market in 2013.

Then, just two years later, Royal Mail sold the remaining third of the company shares it had held onto. The whole organization was now publicly owned. This marked the final transition from a public to a private enterprise for Royal Mail, as well as a solid 499 years of government ownership. Now the citizens of the UK are served by modern company that's run as a company, rather than as a governmental department or crown corporation.

How to Format Royal Mail

Here's the fun part that everyone wants to know about: how do I address a letter to meet UK standards?

Let's start with the example address we listed above:

Cpt. Steven Rogers
221B Baker Street

The address should look like the above. It sits (with a gracious margin on all sides) in the bottom left-hand corner of the face-side of the envelope (the side that doesn't have the flap), with the postage stamp in the opposite, top right-hand corner. Here's the breakdown of the actual address:

  1. The address should start with the name of the addressee
    1. An additional line can be added for a business name if appropriate
  2. Next comes the property number, and street name
  3. The next line contains the city name
    1. The city name should be listed in all caps
    2. A line may be inserted above indicating the town or village, if appropriate
  4. Next is the postal code (we'll discuss that madness in a moment)
  5. Be sure the text is left-aligned, and that there's no commas or periods (the Brits call them "full stops")

Return addresses follow the same format, but are listed on the opposite side of the envelope. As in, on the back side, with the flap, on the bottom right. An international addressee also follows the same format—simply add the country name, fully spelled out and in all caps, as the bottom line.

UK Return Address Format

The address on the bottom left-hand corner of the envelope.

UK Return Address Format

The return address on the bottom right of the envelope's opposite side.

British Postal Codes

A brief warning: British postal codes are kind of...complicated. In the US, the postal code (known as a ZIP Code) is a 5-digit number indicating which post office a piece of mail is headed for (with an additional 1–4 digits added by the USPS, indicating what route it will take when it goes out for delivery). In Canada it's a 6-digit code, where the characters alternate between letters and numbers, with a space in the middle. The first character (always a letter) indicates the postal district, and that's almost always tied to an entire territory or province.

The system that is used in the UK is an alphanumeric system, like Canada's, that varies from 5-7 characters. Let's see if we can make this all make sense. Deep breath, and...let's begin.

First, let's use our example from the address above:


The postal code is divided along the gap into two portions: the "outward" code and the "inward" code. The outward code is the section to the left of the space, and the inward code is what's to the right. Within these two sections are four more components: postcode area, postcode district, postcode sector, and postcode unit. The postcode area is the largest designation, and each following designation is a sub-division of the one before. Here's how they work:

  • The Outward Code ("NW1" from above) is anywhere from 2–4 characters long, and most indicate at least a vague geographical area, though a few are wholly non-indicative of physical location (i.e., they're not tied to the name of the place). The outward code is made up of the following components:
    • Postcode Area (the "NW") is 1–2 characters long, always letters. This denotes the largest postal unit; it's often tied to geographical names or city names, though it's not necessarily indicative of size or scope as postal boundaries don't always match political or geographical boundaries.
    • Postcode District (the "1" character) is 1-2 number characters, with the second character sometimes being a letter instead. This indicates the largest sub-division of the postcode area.
  • The Inward Code (the "6XE" from the example) is always 3 characters, with a number-letter-letter format. It's made up of the following components:
    • Postcode Sector: this one's weird. It's made up of the whole outward code, the space, and then the first character (a number) of the inward code. So the first piece of the inward code is actually the outward code +1 (NW1 6).
    • Postcode Unit: the final two characters (letters) on the inward code. This one's more or less equivalent to the ZIP+4 Codes used in the US. It designates delivery route level specificity: anything from a full street to a sub-section of a building, depending on quantity of mail received on a regular basis. Basically anything in the path the mail truck takes in one go.

See? Piece of cake. Or should we say a crumpet you might have with tea?

Services Offered

Royal Mail has a buffet of options to facilitate different needs amongst its customers. From the minor to the major, they've got something to fit the need, circumstance, and (hopefully) the budget of any customer. Here's the breakdown.

Domestic: anything from the UK to the UK

  • 1st Class: for those of us who want to get our mail there next day (not guaranteed). They also offer a Royal Mail Signed For® 1st Class option, which requires that Royal Mail get a signature on delivery to prove the package was picked up. This only guarantees delivery, not delivery time.
  • 2nd Class: 2–3 business day service, for those of us who don't mind kicking it economy style. There's a Royal Mail Signed For™ option for 2nd Class as well.
  • Special Delivery Guaranteed™: "On time or your money back!" In case 1st class isn't fancy enough for you, get a guarantee that your mail will be in the recipient's hands the very next day. This fancy option comes in two flavours:
    • By 1pm next day: the standard option, it makes sure that the package or letter is at the destination by just after lunch time tomorrow
    • By 9am next day: still not good enough? How about dropping it at their doorstep before they even roll out of bed?
  • Same-day: when you absolutely, positively, irrevocably have to get those animal remains (see below) where they've gotta go. It's available, no joke, 24/7 and 365 days a year. So even Santa Claus can get what he needs if he forgot something in his sleigh.

International: anything from the UK to anywhere else

Here's a big disclaimer—international service through Royal Mail has two flavours. By and large, it's either Western Europe, or "everything else." Europe's easy (go figure). Everything else has more paperwork and takes longer. Below is what they offer.

  • International Economy: for when you want to send a letter to your pen pal, but you don't want to pay £50 for it.
    • Delivery time of 10-15 working days Western Europe.
    • 6-12 weeks for the rest of world.
    • Service is offered worldwide.
  • International Standard: for when you don't want your letter to take 3 months to get there.
    • 3-5 working days delivery time to Western Europe.
    • 5-7 working days turnaround time for countries outside Europe
    • Also a worldwide service.
  • International Signed: in case you want proof it got there, but don't care until it happens.
    • Also 3-5 days for Europe.
    • Also 5-7 days elsewhere.
    • 180 countries serviced.
  • International Tracked: in case you want to follow its progress, but don't care what happens to it when it gets there.
    • Same turnaround times as International Standard.
    • Only 39 countries serviced.
  • International Tracked and Signed: in case you really do care where it is and when it gets there.
    • Turnaround time as good as International Standard.
    • Oddly enough, though Signed offers a reach of 180 countries, and Tracked only offers 39, you get 53 when you put them together.

And that's the gist of it.

British Mail Prohibitions and Restrictions

This stuff is important, because you really don't want your mail thrown away just because you didn't check to see that Royal Mail won't let you ship it. That said, as with all disclaimers and warning labels, we often have to shake our heads and say, "I want to meet the guy this rule was made for."


Let's start with the home territory (there are some differences between domestic and international, and … well, you'll see).

Prohibited items:

These can't be shipped at all.
  • "Aerosols not for personal grooming or medicinal purposes"
  • "Alcoholic beverages with content above 70% ABV"
    • Less intense refreshments are permissible with certain limitations; see below.
  • "Ammunition"
  • "Asbestos"
    • You have to think...someone sent this stuff at some point, didn't they? Why else would they have to make the rule?
  • "Batteries"
    • Just about anything not listed in the long line of restricted batteries, which is a ton, so we're going to generalize here: some batteries good, some batteries bad. Bad batteries are prohibited.
  • "Clinical and medical waste"
    • Pretty much anything from the doctor's office that would go into the biohazard bin can't go in the mail.
  • "Controlled drugs and narcotics"
    • The list actually points out illegal substances. Seems kinda silly to give your illegal products to a company that used to be an arm of the government.
  • "Counterfeit currency, banknotes and postage stamps"
    • Surprise. You can't mail illegal currency.
  • "Dry ice"
    • Wet ice is ok, though, as far as we can tell.
  • "Explosives"
  • "Flammable liquids"
  • "Flammable solids"
    • Pretty much, just fire = no.
    • Wait, did they cover flammable gases yet?
  • "Frozen water"
    • They're on to us; forget what we said about the wet ice.
  • "Gases"
    • Ah, see, there it is. Just a big, blanket "Gases."
  • "Human remains"
    • Wait, what?
    • No really, who would do that?
  • "Infectious substances UN2814 or UN2900"
    • For the same reason we don't want you mailing the flu. Or ebola.
  • "Living creatures, animals and reptiles"
    • Because (evidently) reptiles aren't animals, and animals aren't creatures
      • "Living"...does Schroedinger's cat count?
      • Also, since the exception is insects (well, certain ones), what then is left to be defined as a "creature"?
  • "Lottery tickets"
    • Except UK ones (apparently).
  • "Magnetised material"
    • Man, they are super specific with their limitations on this one: "Magnetised material with a magnetic field strength of 0.418A/m or more at a distance of 4.6m from the outside of the package."
  • "Matches"
    • What part of "No fire" did you not understand?
  • "Poisonous, toxic liquids, solids or gases"
    • Death = bad. Got it.
  • "Radioactive materials"
    • Nobody wants to see the Hulk trapped on a plane.
  • "Solvent-based paints, wood varnishes and enamels"
    • "See Flammable liquids above." Their words, not ours. We're just curious why they haven't used that reference before now.
  • "Tickets and related advertisements for illegal lotteries"
    • Not even the UK kind slip through this one
    • Also, there are illegal lotteries?
  • "Waste, dirt, filth or refuse"
    • That's a lot of effort to avoid using the word "trash."
    • Also, who would want to ship garbage? What, like as a prank? "Hey, here, let me insult you by sending you some refuse, neatly packaged, so that as soon as you open it and realize it for what it is, you can easily dispose of it without having to even dirty your hands." Not a very effective prank.
  • "Weapons"
    • Unless they're the sporty kind (see below). Good show, old boy.

Restricted Items:

Ok, on to the stuff that can be shipped, but only when they conform to certain regulations. We're not going to list the regulations here (the list is long enough); we'll just warn you what's on the list.

  • "Alcoholic beverages and liquids"
    • 24% ABV or less has one set of restrictions.
    • More than 24% ABV but not more than 70% ABV has a different set of restrictions.
  • "Balloons"
    • Applies only to filled balloons; must be non-flammable gas, and clearly marked as such.
    • Also, fire=bad; see prohibited items above.
  • Batteries: this is where the list assaults you with a battery of batteries. The following are types of restricted batteries:
    • "New alkaline metal, nickel metal hydride (NiMH) or nickel cadmium (NiCd)"
    • "Lithium ion/polymer batteries contained in/connected to an electronic device"
    • "Lithium ion/polymer batteries sent with, but not connected to, an electronic device"
    • "Lithium metal/alloy batteries contained in/connected to an electronic device."
    • "Lithium metal/alloy batteries sent with, but not connected to, an electronic device"
    • "Wet non-spillable"
      • A nice, simple one, for a change.
  • "Biological Substances (Category B)"
    • Gross.
  • "Christmas Crackers"
    • We've never seen one, but they sound super awesome.
    • Christmas Cracker snaps, however, are straight up prohibited. Guess it makes sense, since one explodes and one does not.
  • "Counterfeit currency and stamps"
    • So you can ship them, but only certain kinds.
  • And here's another battery of nonsense:
    • "Electronic items sent with new alkaline metal, nickel metal hydride (NiMH) or nickel cadmium (NiCd) batteries"; OR "sent with lithium ion/polymer batteries contained in/connected to the device"; OR "sent with lithium ion/polymer batteries where the battery is not connected to/contained in the device"; OR "sent with lithium metal/alloy batteries contained in/connected to the device"; OR "sent with lithium metal/alloy batteries where the battery is not connected to/contained in the device"
    • We told you the battery stuff went on forever.
  • "Guns for sporting use"
    • So, leave the bullets, ship the gun.
  • "Human or animal samples"
    • Wait, what?
  • "Lighters"
    • Must be new, unused, and empty. The fuel is, of course, prohibited (see the "no fire" section above).
  • "Living creatures, insects and invertebrates"
    • Now that's a practical joke.
  • "Perishable items"
    • So you could ship milk, in theory...
  • "Radioactive material and samples that are not classified as dangerous goods in the latest edition of the Technical Instructions for the Safe Transport of Dangerous Goods by Air published by the International Civil Aviation Organization (ICAO) such as samples of granite rock"
    • We just like this one because it's ridiculously long.
  • Sharp Objects.
    • Don't want to pop the balloons.


Now for what can't be shipped across the pond. Since a lot of this list is the same as above, we will omit the boring parts, and we'll only reuse our jokes where we deem expressly necessary.


Most of the rules and regulations are the same as above. Here are a few items that differ from the list you just read:

  • "Alcohol"
    • They're stricter this time: they cut you off after 24%.
  • "Counterfeit currency, banknotes and postage stamps"
    • Seriously, who's shipping this stuff?
  • "Living creatures, insects and invertebrates"
    • You would really ship living creatures via transport that could take up to three months?
  • "Sharp objects"
    • Balloons are, evidently, more dangerous this time around; see below.


We promised you more entertainment. Here it comes.

  • "Asbestos"
    • No exception. Nobody wants it anyway, in the UK or elsewhere.
  • "Balloons filled with non-flammable gas"
    • So, pretty much no filled balloons? Or can you fill them with liquids? If so, for what purpose? An international water balloon fight?
    • Also, aren't they going to mention the flammable gas part? Or are they just going to wait until it comes up in its own section later? Why not just say "No filled balloons"?
  • "Clinical and medical waste"
    • That really is a long way to the bin.
  • "Explosives"
  • "Flammable liquids"
  • "Flammable solids"
  • "Gases"
    • Seriously guys, "no fire" should be simple enough.
    • Also, this is the part that should have been mentioned with the balloons.
  • "Goods made in foreign prisons"
    • Wait, what?
  • "Human and animal remains"
    • "Remains" . . . does Schroedinger's cat count here?
  • "Liquids over 1 litre"
  • "Living creatures, animals and reptiles"
    • "Living" . . . or does Schroedinger's cat count here?
  • "Lottery tickets"
    • No exceptions this time. They don't want you bringing down the $80 million powerball from Germany. Like it was actually going to happen.
  • "Matches"
    • Because, you know, fire.
  • "Solvent-based paints, wood varnishes and enamels"
    • Seriously, this is just a list of things that burn.
  • "Tickets and related advertisements for illegal lotteries"
    • Because, you know, open advertisement of illegal activities is such a good idea.
  • "Weapons"
    • Unless you're a good sport (see above).

Business shipments have a few adjustments to the rules. We won't go into detail here, since we've already stretched things on a bit. But for the most part, the above rules apply.

Undeliverable Mail

One last bullet list (we promise this one is short). Sometimes Royal Mail can't get your postage where it's going. Here are the possible reasons why, in their own words:

  • The mail wasn't addressed properly or part of the address was missing.
  • The building no longer exists (for example if it's been demolished).
  • The person receiving the mail refused to accept it.
  • Insecure packing meant an address label came off.
  • Not enough postage has been paid and no one will pay the fee.
  • There's a security system at the delivery address which stopped us from gaining access.
  • There was no one at home to receive mail which requires a signature, or the item is too big to put through the letterbox.
  • If the delivery address isn't permanently occupied, or if access is unsafe, impractical or unreasonable. If this happens, we'll try to contact whoever the mail is addressed to and ask them to collect it. If we can't get hold of them, or they don't collect the mail in time, unfortunately we'll have to treat it as undeliverable.
  • If the item has been sent to an address outside the UK using a service that isn't accepted by the country it's addressed to, it will be returned to the sender

We bring this up because, as an international address validation (also known as address verification) company, it's our job to help people avoid "undeliverable" type problems. We do that by checking the address you're shipping to against an authoritative database to see if it's on the list. If the address is on record, it validates, and we can tell you for sure that it's a real address, and someone is really receiving mail at that location currently. If it's not on record, it's an invalid address, and while the reasons for that vary the result is the same—it will be undeliverable.

So feel free to validate the address first, or call our our customer support direct line. We'd be more than happy to help you out and answer your questions. And if we can't get you what you need, we'll help you find where you can.


Royal Mail is the current incarnation of one of the oldest postal organizations in the world. It has a rich history, and the methods, tools, and tactics developed pursuant to the delivery of mail in the UK have influenced postal systems around the world (just look at the stamp). For the most part, if you live in an English-speaking country, you probably have Royal Mail to thank for the fact that your Amazon packages know how to get to your front door with any degree of efficiency.

If you find yourself in need of their services sometime in the future, just remember that you're taking part in a legacy that predates Shakespeare and has found a way to survive and move forward even in a day where paper mail is nearly a thing of the past.

In other words, Royal Mail's an old dog that taught itself quite a few new tricks over the course of almost 500 years. Just don't try to ship that dog internationally.

You may or may not have a chance with the cat, though.

Ready to get started?