In England, based on the Marriage Act of 1836 and the Births and Deaths Registration Act of 1836 the Civil Registration of Births, Marriages and Deaths started on 1st July 1837 In Scotland such registration became compulsory for all in 1855 and for Ireland it was 1 864 for births & deaths and 1845 for marriages. After 1927 still births and adoptions were added to the register.
Although registration was introduced in 1837 it was not compulsory to make the registration until 1874, Prior to 1874 the onus was on the Registrar for the area to find out the details. The registration of Births and Deaths act of 1874 firmed up on the requirements making the next of kin responsible for registration, in the case of births within 42 days but for deaths you had a year. For marriages this was normally done by liaison with the churches, but if anyone married outside the Church of England the marriage could be missed. Many assumed that by getting married in church the registration was automatic but this was also not always the case. Births were even more difficult with babies being born at home in remote locations the registrar may never find out. People also genuinely assumed that baptism of a child automatically registered them, it did not. Deaths were a bit more accurate as you had to have a certificate of death to perform burial, though that does not mean that some died and were buried in remote locations without any paperwork. Some sources suggest that in the early days as little as 50% of all events actually got registered as they should, and even by 1874 only 85% of events were registered, so the fact you can not find your relatives in the records does not mean they did not exist.
There is further information on Civil Registration on the GENUKI website GENUKI - Civil Registration.
There are actually two indexes to these registrations, the first is held by the registration office where the registration was made and the second national index is held by General Register Office. Both have different indexing systems so you need to look in the appropriate index depending on where you want to obtain the certificate copy from. In general most of the BMD indexes on line use GRO references and not local ones.
All registrations were made to the local registration district and in Cumbria some of these can be quite large and you may find registrations in unexpected places. Each registration office normally holds the registrations in date order by parish so it helps a lot if you know which parish to look at when dealing with a local office. Once a quarter all registrations are sent in to the GRO where the returns from a region are pooled and an alphabetical index is created for that quarter. Each area has a volume and for Cumbria this is Volume XXV (25) prior to 1851 and Volume 10b after 1851 when the volume numbers were changed. Even though the Furness area was in Lancashire prior to 1974 the majority of the registrations are in the same volumes as Cumberland and Westmorland.
Prior to about 1937 the following districts cover what is current day Cumbria:
After 1937 there were some changes to the divisions, the main one being Westmorland being divided into Westmorland North and Westmorland South instead of the previous divisions. Then of course the major change n 1974 when Cumbria was formed.
To get the marriage or death certificate, or birth certificate you will need a reference, if you know the approximate date you need to consult the GRO index. You can do this in person at the Family Records Office or there are many locations on line where you can search the database. Some are free but some charge a small fee to access, typically this will be in the order of £5 for a months access. Be careful if signing up on line as many sites auto renew your subscription so you must make sure to cancel it when you are finished researching. If you set by some time then a month will be more than enough to get the data you need. A good place to start is the FreeBMD website whilst this can not be guaranteed to have 100% of records you will find most Births Marriages and Deaths from Late 1837 through to well into the 1900's, just remember that not finding in here does not mean it does not exist and that there are always transcription errors that could make some names difficult to find. See below for more information on FreeBMD
At the time of writing this you can also search the UK database 1837-1983 free (though you will have to register) at Ancestry Marriage Database Ancestry Birth Database Ancestry Death Database (It is not known how long they will keep this free of charge though) this will enable you to view the page relevant to your names and period and to extract the volume and page number data for the event concerned.
A third source of information is via the UKBMD website. This does not actually have the actual information, it is more a portal which has links to various sites where you may find information, some of these sites will be subscription sites.
You can also search on the Government Records Office website GRO. You will need to register ] to use the website but it is free to do so. There is also a lot of useful family history information on thier website.
Once you have this data you can order the certificate from the GRO The cost if you order on line is from £11.00, it may be slightly more if you order by phone, fax or mail or if you can not supply the full reference, though they have recently simplified charging so that you do not always have to provide a reference, provided you can supply enough information for them to find it. You can also request the information by PDF, you will get exactly the same information but electronically delivered as a PDF file, in this case the charge is £7, the only difference is that the PDF is not a legal document wheras the more expensive paper document it. If you wish to verify the details then there is really no alternative but to obtain the relevant certificate. The charge is the same whether you are in UK or overseas. Beware of other agencies who provide certificates as they are invariably more expensive than direct from the GRO and exactly the same certificate is provided.
If you obtain the certificate from the GRO, they will issue it regardless of details provided the name matches the name you have provided. An advantage to ordering from the local records office is that you can specify them to only issue the certificate if certain other matches are made, for example only to issue the birth certificate for John Smith if his fathers name was George. This can save you money as they will not charge if there is no complete match.
You do not have to obtain the certificates if the index provides the information you need and establishes the identity of your family member. It also depends as to whether you wish to have definite source information for that record. Certificates can help to establish the correct person however, you may for example find two John Smith's registered in the same area in the same year, which one is yours? Obtaining the certificate with the parents details and address may help resolve that problem.
This is the Free Births Marriages and Deaths site, as the title suggests it is also totally free to use. However as records are still being added not all locations and years are yet in place. Bear in mind that records only started in 1837 so there are no records in here prior to that date, before 1837 your only source is the IGI or the church parish records. Note these records are for England and Wales only, they do not cover Scotland.
You can access the FreeBMD at Free BMD. There are a number of ways of searching here and you can in fact search scans of the original records even where they have not yet been transcribed. But at first just try on the type, name and date as well as the location. If your ancestors are included you will then get a result showing possible matches, if you now click on the page number link next to any entry it will give you the details on that page. You now have the volume number and page as well as the date (quarter) which is what is needed to obtain the certificate from the GRO. If you plan to use the local record office, then the year/quarter and name are normally all they will need.
Clicking on the spectacles to the right of the name will let you know who transcribed the information so that corrections can be made and it will allow you to see the original index image. It is not immediately obvious how to view the image, you must click on the required image, select the format you require in the list at the right and then click on the 'View The Original' icon at the left of the screen.
At November 2019 the following is the approximate status of the Free BMD
Although completion may be shown at 100% there can be reasons entries are missing, this is in part due to GRO records only being accurate to the nearest thousand and when being transcribed a dual entry can be created when two transcribers enter the same record but differently. You can of course read the original indexes on this site, though this can be a laborious process if you are having to cover a number of years.
Please also bear in mind that although registration came in during the second quarter 1837 some events just did not get registered especially in remote areas. These registrations are only for England and Wales, registration in Scotland did not start until 1 January 1855. The only way to get Scottish Records is via the Scotlands People website and this has to be paid for though you can read the index free of charge.