I have copies of spring and autumn registers between 1919 and 1927 for several of my ancestors. A quick google shows that, "Registers between 1918 and 1926 were compiled in Spring and Autumn of each year. Annual registers were resumed under the Economy (Miscellaneous Provisions) Act, 1926 (16 and 17 George 5, c9)", although interesting that the quote from Surrey FHS indicates a one year discrepancy at each end of that period?