diff --git a/DESCRIPTION b/DESCRIPTION
index 4521ef5..2f90514 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: readabs
 Type: Package
 Title: Download and Tidy Time Series Data from the Australian Bureau of Statistics
-Version: 0.4.20
+Version: 0.4.30
 Authors@R: c(
            person("Matt", "Cowgill", role = c("aut", "cre"), email = "mattcowgill@gmail.com", comment = c(ORCID = "0000-0003-0422-3300")),
            person("Zoe", "Meers", role = "aut", email = "zoe.meers@sydney.edu.au"),
@@ -35,7 +35,6 @@ Imports:
     labelled
 URL: https://github.com/mattcowgill/readabs
 BugReports: https://github.com/mattcowgill/readabs/issues
-RoxygenNote: 7.3.2
 VignetteBuilder: knitr
 Suggests: 
     knitr,
@@ -44,3 +43,4 @@ Suggests:
     testthat (>= 2.1.0),
     ggplot2
 Roxygen: list(markdown = TRUE)
+Config/roxygen2/version: 8.0.0
diff --git a/NEWS.md b/NEWS.md
index 9e339bc..33a8d78 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,6 @@
+# readabs 0.4.30
+* BREAKING CHANGE to read_cpi() in light of changes to the CPI (move to monthly collection). Now has a `frequency` argument that controls whether the quarterly or monthly data is returned.
+
 # readabs 0.4.20
 * Minor bug fixes
 
diff --git a/R/read_cpi.R b/R/read_cpi.R
index 0b94723..1322aa3 100644
--- a/R/read_cpi.R
+++ b/R/read_cpi.R
@@ -1,26 +1,22 @@
 #' Download a tidy tibble containing the Consumer Price Index from the ABS
 #'
 #' \code{read_cpi()} uses the \code{read_abs()} function to download, import,
-#' and tidy the Consumer Price Index from the ABS. It returns a tibble
+#' and tidy the quarterly Consumer Price Index from the ABS. It returns a tibble
 #' containing two columns: the date and the CPI index value that corresponds
 #' to that date. This makes joining the CPI to another dataframe easy.
 #' \code{read_cpi()} returns the original (ie. not seasonally adjusted)
 #' all groups CPI for Australia. If you want the analytical series
-#' (eg. seasonally adjusted CPI, or trimmed mean CPI), you can use
+#' (eg. seasonally adjusted CPI, or trimmed mean CPI) or monthly series, you can use
 #' \code{read_abs()}.
 #'
+#' By default, `read_abs()` retrieves the quarterly CPI. It can use the
+#' `frequency` argument to change to monthly.
+#'
 #' @param path character; default is "data/ABS". Only used if
 #' retain_files is set to TRUE. Local directory in which to save
 #' downloaded ABS time series spreadsheets.
-#'
-#' @param show_progress_bars logical; TRUE by default. If set to FALSE, progress
-#' bars will not be shown when ABS spreadsheets are downloading.
-#'
-#' @param check_local logical; FALSE by default. See \code{?read_abs}.
-#'
-#' @param retain_files logical; FALSE by default. When TRUE, the spreadsheets
-#' downloaded from the ABS website will be saved in the
-#' directory specified with 'path'.
+#' @param frequency Either `"quarterly"` (the default) or `"monthly"`.
+#' @param ... Arguments passed to `read_abs()`. See `?read_abs` for details.
 #'
 #' @examples
 #'
@@ -36,38 +32,28 @@
 #'
 #' @export
 
-read_cpi <- function(path = Sys.getenv("R_READABS_PATH", unset = tempdir()),
-                     show_progress_bars = TRUE,
-                     check_local = FALSE,
-                     retain_files = FALSE) {
-  if (!is.logical(retain_files)) {
-    stop("`retain_files` must be either `TRUE` or `FALSE`.")
-  }
+read_cpi <- function(frequency = c("quarterly", "monthly"),
+                     path = Sys.getenv("R_READABS_PATH", unset = tempdir()),
+                     ...) {
 
-  if (!is.logical(show_progress_bars)) {
-    stop("`show_progress_bars` must be either `TRUE` or `FALSE`")
-  }
+  frequency <- match.arg(frequency)
+
+  cpi_series_id <- switch (frequency,
+    "quarterly" = "A2325846C",
+    "monthly" = "A130393720C"
+  )
 
-  if (retain_files == TRUE & !is.character(path)) {
-    stop(
-      "If `retain_files` is `TRUE`,",
-      " you must specify a valid file path in `path`."
-    )
-  }
 
-  cpi_raw <- read_abs(
-    cat_no = "6401.0",
-    tables = 1,
-    retain_files = retain_files,
-    check_local = check_local,
-    show_progress_bars = show_progress_bars,
-    path = path
+  cpi_raw <- read_abs_series(
+    series_id = cpi_series_id,
+    ...
   )
 
+  series_name <- unique(cpi_raw$series)
+
+  stopifnot(series_name == "Index Numbers ;  All groups CPI ;  Australia ;")
+
   x <- cpi_raw %>%
-    dplyr::filter(
-      .data$series == "Index Numbers ;  All groups CPI ;  Australia ;"
-    ) %>%
     dplyr::select("date",
       "cpi" = "value"
     )
diff --git a/R/sysdata.rda b/R/sysdata.rda
index 4aeef11..d078f86 100644
Binary files a/R/sysdata.rda and b/R/sysdata.rda differ
diff --git a/man/download_abs_data_cube.Rd b/man/download_abs_data_cube.Rd
index 18a2687..27cd9b3 100644
--- a/man/download_abs_data_cube.Rd
+++ b/man/download_abs_data_cube.Rd
@@ -62,9 +62,9 @@ download_abs_data_cube(
 
 }
 \seealso{
-Other data cube functions: 
-\code{\link{search_catalogues}()},
-\code{\link{show_available_catalogues}()},
-\code{\link{show_available_files}()}
+Other data cube functions:
+\code{\link[=search_catalogues]{search_catalogues()}},
+\code{\link[=show_available_catalogues]{show_available_catalogues()}},
+\code{\link[=show_available_files]{show_available_files()}}
 }
 \concept{data cube functions}
diff --git a/man/read_cpi.Rd b/man/read_cpi.Rd
index a739451..7cca917 100644
--- a/man/read_cpi.Rd
+++ b/man/read_cpi.Rd
@@ -5,36 +5,34 @@
 \title{Download a tidy tibble containing the Consumer Price Index from the ABS}
 \usage{
 read_cpi(
+  frequency = c("quarterly", "monthly"),
   path = Sys.getenv("R_READABS_PATH", unset = tempdir()),
-  show_progress_bars = TRUE,
-  check_local = FALSE,
-  retain_files = FALSE
+  ...
 )
 }
 \arguments{
+\item{frequency}{Either \code{"quarterly"} (the default) or \code{"monthly"}.}
+
 \item{path}{character; default is "data/ABS". Only used if
 retain_files is set to TRUE. Local directory in which to save
 downloaded ABS time series spreadsheets.}
 
-\item{show_progress_bars}{logical; TRUE by default. If set to FALSE, progress
-bars will not be shown when ABS spreadsheets are downloading.}
-
-\item{check_local}{logical; FALSE by default. See \code{?read_abs}.}
-
-\item{retain_files}{logical; FALSE by default. When TRUE, the spreadsheets
-downloaded from the ABS website will be saved in the
-directory specified with 'path'.}
+\item{...}{Arguments passed to \code{read_abs()}. See \code{?read_abs} for details.}
 }
 \description{
 \code{read_cpi()} uses the \code{read_abs()} function to download, import,
-and tidy the Consumer Price Index from the ABS. It returns a tibble
+and tidy the quarterly Consumer Price Index from the ABS. It returns a tibble
 containing two columns: the date and the CPI index value that corresponds
 to that date. This makes joining the CPI to another dataframe easy.
 \code{read_cpi()} returns the original (ie. not seasonally adjusted)
 all groups CPI for Australia. If you want the analytical series
-(eg. seasonally adjusted CPI, or trimmed mean CPI), you can use
+(eg. seasonally adjusted CPI, or trimmed mean CPI) or monthly series, you can use
 \code{read_abs()}.
 }
+\details{
+By default, \code{read_abs()} retrieves the quarterly CPI. It can use the
+\code{frequency} argument to change to monthly.
+}
 \examples{
 
 # Create a tibble called 'cpi' that contains the CPI index
diff --git a/man/search_catalogues.Rd b/man/search_catalogues.Rd
index 9369de4..3ebd561 100644
--- a/man/search_catalogues.Rd
+++ b/man/search_catalogues.Rd
@@ -31,9 +31,9 @@ a given string in the catalogue names, product title, and broad topic.
 search_catalogues("labour")
 }
 \seealso{
-Other data cube functions: 
-\code{\link{download_abs_data_cube}()},
-\code{\link{show_available_catalogues}()},
-\code{\link{show_available_files}()}
+Other data cube functions:
+\code{\link[=download_abs_data_cube]{download_abs_data_cube()}},
+\code{\link[=show_available_catalogues]{show_available_catalogues()}},
+\code{\link[=show_available_files]{show_available_files()}}
 }
 \concept{data cube functions}
diff --git a/man/show_available_catalogues.Rd b/man/show_available_catalogues.Rd
index 4eebc60..b89fb7d 100644
--- a/man/show_available_catalogues.Rd
+++ b/man/show_available_catalogues.Rd
@@ -25,9 +25,9 @@ These catalogues must be specified as a string as an argument to \code{download_
 show_available_catalogues("Earnings and work hours")
 }
 \seealso{
-Other data cube functions: 
-\code{\link{download_abs_data_cube}()},
-\code{\link{search_catalogues}()},
-\code{\link{show_available_files}()}
+Other data cube functions:
+\code{\link[=download_abs_data_cube]{download_abs_data_cube()}},
+\code{\link[=search_catalogues]{search_catalogues()}},
+\code{\link[=show_available_files]{show_available_files()}}
 }
 \concept{data cube functions}
diff --git a/man/show_available_files.Rd b/man/show_available_files.Rd
index 2d0c8a3..3a6926e 100644
--- a/man/show_available_files.Rd
+++ b/man/show_available_files.Rd
@@ -40,14 +40,9 @@ show_available_files("labour-force-australia-detailed")
 
 }
 \seealso{
-Other data cube functions: 
-\code{\link{download_abs_data_cube}()},
-\code{\link{search_catalogues}()},
-\code{\link{show_available_catalogues}()}
-
-Other data cube functions: 
-\code{\link{download_abs_data_cube}()},
-\code{\link{search_catalogues}()},
-\code{\link{show_available_catalogues}()}
+Other data cube functions:
+\code{\link[=download_abs_data_cube]{download_abs_data_cube()}},
+\code{\link[=search_catalogues]{search_catalogues()}},
+\code{\link[=show_available_catalogues]{show_available_catalogues()}}
 }
 \concept{data cube functions}
diff --git a/tests/testthat/test-readabs.R b/tests/testthat/test-readabs.R
index 636669e..e126fe6 100644
--- a/tests/testthat/test-readabs.R
+++ b/tests/testthat/test-readabs.R
@@ -138,6 +138,13 @@ test_that("read_cpi() function downloads CPI index numbers", {
     cpi$cpi[cpi$date == date_12m_before_latest]) - 1
   expect_gt(latest_annual_inflation, -.02)
   expect_lt(latest_annual_inflation, 0.1)
+
+  # Test that default is quarterly
+  expect_equal(min(cpi$date), as.Date("1948-09-01"))
+
+  cpi_m <- read_cpi("monthly")
+  expect_equal(min(cpi_m$date), as.Date("2024-04-01"))
+
 })
 
 test_that("read_cpi() returns appropriate errors", {
@@ -147,7 +154,6 @@ test_that("read_cpi() returns appropriate errors", {
 
   expect_error(read_cpi(retain_files = NULL))
   expect_error(read_cpi(show_progress_bars = NULL))
-  expect_error(read_cpi(retain_files = TRUE, path = 1))
 })
 
 test_that("3401.0 table 1 can be loaded", {