Set NotBlank property to false when No. Series TableRelation exists
When a table includes a field with a TableRelation to “No. Series”, the primary key value is typically assigned in the OnInsert trigger through number series management. The platform validates NotBlank on the primary key field before the OnInsert trigger runs.
If NotBlank = true on the primary key, creating a new record from the client fails immediately. The user sees a validation error before the number series logic gets a chance to assign a value.

The NotBlank validation fires before the OnInsert trigger assigns a number.
Set NotBlank = false on the primary key field, or remove the property entirely.
Example
The following table has a “No. Series” relationship but incorrectly sets NotBlank = true on the primary key:
table 50100 "Service Request"
{
fields
{
field(1; "No."; Code[20])
{
NotBlank = true; // Set NotBlank property to false when 'No. Series' TableRelation exists [AC0003]
}
field(2; Description; Text[100]) { }
field(3; Type; Enum MyType) { }
field(4; "No. Series"; Code[20])
{
TableRelation = "No. Series";
}
}
keys
{
key(PK; "No.")
{
Clustered = true;
}
}
trigger OnInsert()
var
NoSeries: Codeunit "No. Series";
begin
Rec."No." := NoSeries.GetNextNo('MyNumberSeriesFromSetup');
end;
}When the diagnostic is reported
- The table has a single-field primary key of type Code or Text with
NotBlank = true - Any field in the table has a
TableRelationpointing to “No. Series” - The primary key field is not named “Name” (see exception below)
Journal Templates
There is an exception to this rule, for (custom) Journal Template tables.
Journal Template tables use “Name” as their primary key rather than “No.” and require NotBlank = true to prevent blank template names, even though they include a “No. Series” TableRelation. The rule excludes tables where the primary key field is named “Name”.
field(1; Name; Code[10])
{
Caption = 'Name';
NotBlank = true;
}
...
field(16; "No. Series"; Code[20])
{
Caption = 'No. Series';
TableRelation = "No. Series";
trigger OnValidate()
begin
if "No. Series" <> '' then begin
if Recurring then
Error(
Text000,
FieldCaption("Posting No. Series"));
if "No. Series" = "Posting No. Series" then
"Posting No. Series" := '';
end;
end;
}See also
- NotBlank Property on Microsoft Learn
- AC0002 — Single-field primary key requires the NotBlank property