Building a Fee payment table

Here is an example code that shows one way to do this.
You can change the endYear value to lengthen or shorthen the forecast period.

let
    endYear = 2026,
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45W8s3PK8nIqVTSUTI1ABKG+ob6RgZGpkqxOshy5qZAwkjfFCEXWJpYVJJaBJY1NMDQiiINNtkIl7QR1GIjA4S8Y15eaWIOUNgEzehYAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Frequency = _t, Amount = _t, #"Last Payment Date" = _t]),
    set_types = Table.TransformColumnTypes(Source,{{"Frequency", type text}, {"Amount", Int64.Type}, {"Last Payment Date", type date}}),
    add_freq_months = Table.AddColumn(set_types, "Frequency Months", each if [Frequency] = "Monthly" then 1 else if [Frequency] = "Quarterly" then 3 else if [Frequency] = "Annual" then 12 else 0, Int64.Type),
    generate_paid_months = Table.AddColumn(add_freq_months, "Dates", each let freq = [Frequency Months], startDate = Date.StartOfMonth([Last Payment Date]), amount = [Amount] in List.Generate(()=> startDate, each _ <= #date(endYear,12,1), each Date.AddMonths(_, freq), each Date.ToText(_)&"|"&Number.ToText(amount))),
    convert_list_to_table = Table.TransformColumns(generate_paid_months, {{"Dates", each Table.FromList(_, Splitter.SplitTextByDelimiter("|"), {"Date", "Amount"})}}),
    transpose_nested_tables = Table.TransformColumns(convert_list_to_table, {{"Dates", each Table.PromoteHeaders(Table.Transpose(_))}}),
    minPaymentMonth = Date.StartOfMonth(List.Min(transpose_nested_tables[Last Payment Date])),
    minFrequencyMonths = List.Min(transpose_nested_tables[Frequency Months]),
    generatedDatesList = List.Generate(()=> minPaymentMonth, each _ <= #date(endYear,12,1), each Date.AddMonths(_, 1), each Date.ToText(_)),
    expand_nested_tables = Table.ExpandTableColumn(transpose_nested_tables, "Dates", generatedDatesList),
    remove_freq_months = Table.RemoveColumns(expand_nested_tables,{"Frequency Months"})
in
    remove_freq_months

Using your example data...

You end up with...

Hope this gets you pointed in the right direction.

let
    // fact_table is your original table
    fx_schedule = (row) => ((sequence) => Record.FromList(List.Repeat({row[Amount]}, List.Count(sequence)), sequence))
        (List.Generate(
            () => row[Last Payment Date], 
            (x) => x <= last_month, 
            (x) => Function.Invoke(Record.Field(freq, row[Frequency]), {x, 1}),
            (x) => Date.ToText(x, "MMM-yy")
        )),
    freq = [Monthly = Date.AddMonths, Quarterly = Date.AddQuarters, Annual = Date.AddYears],
    last_month = Date.AddMonths(Date.EndOfMonth(Date.From(DateTime.FixedLocalNow())), 12), 
    headers = List.Generate(
        () => List.Min(fact_table[Last Payment Date]), 
        (x) => x <= last_month, 
        (x) => Date.AddMonths(x, 1),
        (x) => Date.ToText(x, "MMM-yy")
    ),
    schedule = Table.AddColumn(fact_table, "expand_me", fx_schedule), 
    xpand = Table.ExpandRecordColumn(schedule, "expand_me", headers)
in
    xpand

Hi JoeHeraty, I've created another query for you:

you can select DateType and WeekType

Output if you select Date = 1 (only weeks with payments)

Output if you select Date = 0 (full year)

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45W8s3PK8nIqVTSUTI1ABIGhvpAZGRgZKoUq4Msa24KkjXVNzBCyAaWJhaVpBaB5Q0NsGhHUQA3H4cJRmAFRgYoJjjm5ZUm5gDFTTDMjwUA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Frequency = _t, Amount = _t, #"Last Payment Date" = _t]),
    ChangedType = Table.TransformColumnTypes(Source,{{"Amount", Currency.Type}, {"Last Payment Date", type date}}, "sk-SK"),
    __Select__ = [ 
        DateType = 0,   // 0 = Full year,   1 = Use only weeks with payments
        WeekType = 0    // 1 = Ordinary,    1 = ISO
  ],
    D = [ firstDate = if (__Select__[DateType] ?? 0) = 0 then Date.StartOfYear(List.Min(ChangedType[Last Payment Date])) else List.Min(ChangedType[Last Payment Date]),
    lastDate = Date.EndOfYear(firstDate),
    weeks = Record.Combine(List.Generate(()=> firstDate, each _ <= lastDate, each Date.AddDays(_, 7), each Record.AddField([], Date.ToText(firstDate, "yyyy") & "-W" & Text.PadStart(Text.From(Date.WeekOfYear(_)), 2, "0"), null))) ],
    Fn_Week = (Data as date) =>
            let
                Weekday = Date.DayOfWeek(Data) + 1,
                Part1 = Number.From(Data) - Weekday + 11,
                Part2 = Number.From(#date(Date.Year(Date.From(Number.From(Data) + 4 - Weekday)),1,1)),
                Part3 = (Part1 - Part2) / 7,
                Tranc = Part3 - Number.Mod(Part3, 1),
                Output = Date.ToText(D[firstDate], "yyyy") & "-W" &
                                ( if __Select__[WeekType] = 1
                                  then Text.PadStart(Text.From(Tranc), 2, "0")
                                  else Text.PadStart(Text.From(Date.WeekOfYear(Data)), 2, "0")
                                )
            in
                Output,
    StepBack = ChangedType,
    Ad_Weeks = Table.AddColumn(StepBack, "Weeks", each 
        [ a = if [Frequency] = "Annual" then {Record.AddField([], Fn_Week([Last Payment Date]), [Amount])} else List.Generate(
                    ()=> D[firstDate],
                    (x)=> x <= D[lastDate],
                    (x)=> if [Frequency] = "Weekly" then Date.AddDays(x, 7) else
                            if [Frequency] = "Monthly" then Date.AddMonths(x, 1)
                            else Date.AddQuarters(x, 1),
                    (x)=> Record.AddField([], Fn_Week(x), [Amount])),
          b = _ & Record.Combine(a)
        ][b]
    , type table),
    UsedSelectedDate = [ fn = each Table.Skip(Table.Combine(List.Transform(_[Weeks], (x)=> Table.FromRecords({x})))),
    a = Table.InsertRows(Ad_Weeks, 0, { Ad_Weeks{0} & [Weeks = Record.Combine(List.Transform(List.RemoveMatchingItems(Table.ColumnNames(Ad_Weeks), {"Weeks"}), (x)=> Record.AddField([], x, null))) & D[weeks]] }),
    b = if __Select__[DateType] = 1 then fn(Ad_Weeks) else fn(a)
  ][b],
    ChangedType2 = Value.ReplaceType(
        UsedSelectedDate,
        Value.Type(Table.FirstN(ChangedType, 0) &
          [ a = List.Difference(Table.ColumnNames(UsedSelectedDate), Table.ColumnNames(ChangedType)),
            b = Table.PromoteHeaders(Table.FromRows({a})),
            c = Table.TransformColumnTypes(b, List.Transform(a, (x)=> {x, Currency.Type}))
          ][c] ))
in
    ChangedType2

Hi JoeHeraty,
Thanks for reaching out to the Microsoft fabric community forum.

It looks like the issue you were having has been solved by jgeddes. Please accept it as solution if you are satisfied with the solution.

If I misunderstand your needs or you still have problems on it, please feel free to let us know.
Best Regards,
Hammad.
Community Support Team

If this post helps then please mark it as a solution, so that other members find it more quickly.
Thank you.