It is not a business, but for those with multiple properties. It is also a pain if you ordering something for a home in one country and paying with a card from another country if your purchase fails on an AVS check. 
Monzo don’t have SecureCode yet, but do plan to implement it at some point. Probably when version 2.0 comes out!
Just to emphasize again that you are not taking any risk at all. Should someone else use your card without your permission, then (unless you have been negligent) your bank will reimburse you, including any overdraft fees you may have incurred. In my experience all banks will do that without even asking questions: Just tell them “this transaction wasn’t me” and they’ll refund you on the spot.
And if a merchant accepts a card after being told by the bank that the billing address doesn’t match the address on their record, then the bank can seek redress from the merchant, after having refunded you the money. However, that has no impact on you whatsoever: Address checking is done purely to shift responsibility for fraudulent transactions between bank and merchant, but your point of call is always the bank, and you will always get your refund through them.
This times a million!
For reference: I deal with these sort of queries all the time in my day job. Address verification fails a lot due to formatting differences: Maybe people write their address as “11, Some Steet”, but the bank has “11 Some Street”, or some shop interfaces - usually by American merchants - expect you to enter your “State” with a mandatory field, which can be impossible if you live in Greater London, and the list of “states” only lists counties. I’ve seen all sorts of nonsense.
This is something I wondered before but chalked it up to how careful the site wanted to be. I have had transactions that were declined because the address format was wrong, and others where the address was entirely different but went through fine.
I’m not sure if it’s Amazon or Asda or Aliexpress but I remember payments going through fine (onto my new card) after I lost my previous card and it was cancelled. I didn’t change the saved card. The billing address was different too. Confusing, but somehow it works? 
do they save the bank account number instead of the card number? It happened with Santander too
Amazon is happy to take a lot of risks with card payments: They don’t even check CVVs, and I’m pretty sure you can enter any address you wish as billing address.
Also, it is entirely possible for payments to still go through against a cancelled card. Could happen if the payment was already authorised at the time that the card was cancelled, or if it’s an “offline” transaction, i.e. the merchant just turns up at the bank saying “we’d like to have £££ please”, without seeking an authorisation first. In that case, the bank can accept or decline the request at its discretion, but will usually default to accepting it. (This used to happen a lot in “the olden days” when contactless cards were offline. Nowadays it’s getting rarer, but I don’t think Amazon ordinarily authorises payments before collections, but posts most payments as offline transactions, so that would explain this.)
We can agree to disagree. It makes sense to have at least a vaguely matching address.
And please, this argument that you’ll get the money back. I know I will. But to some people any money going out of their accounts unexpectedly can cause issues, even if they get it back relatively quick. I tire of people using that as a reasons for risk, and usually they are the people who can afford to go a couple of days without some money in their account.
Like I said, agree to disagree. Generally I don’t want my bank authorising charges if there is some questioning as to the validity of the purchase.
No, sorry, that’s not possible on the internet!
Ha we can agree to disagree on that.
And so begins the loop…
No, no, no!
I had an issue using the Royal Mail website yesterday and it declined 3 times. I wasn’t sure whether is was because I had just changed my address in the app. I did however try it with old and new addresses and no luck. Anyone have any ideas? I have contacted support but no reply since yesterday.