If a respondent reports they can't get past a required field, walk through the block-specific validation rules.
Email validation
The Email block enforces a basic format check (name@domain.tld). Common reasons it rejects an entry:
- Leading or trailing spaces around the address — paste-then-trim is needed.
- Missing TLD:
foo@barwithout the.comwill fail. - Quoted local parts or unusual characters that strict regex doesn't allow.
We do not verify the address actually receives mail — that requires sending a confirmation email, which NodumForms doesn't do by default.
Phone validation
The Phone block is lenient. It accepts digits, spaces, dashes, parentheses, and the + symbol. International numbers with country codes are fine. We don't validate the country code matches the digit count.
Common reasons it rejects: letters in the entry, or unusual punctuation like periods between digits.
File upload validation
Files must be:
- Under the per-file size limit (default 5MB, configurable per block up to ~25MB).
- Within the file count limit (default 5 files per submission, configurable per block).
- One of the allowed formats: PDF, DOC, DOCX, PNG, JPG, JPEG, GIF, WEBP. ZIPs, EXEs, and other formats are rejected.
If the respondent uploads multiple files and one is too large, the whole batch is rejected — they need to remove the offending file and retry.
Required vs optional
A red asterisk (✱) next to the question label means the block is required. The Submit button is disabled until every required field has a value. Optional blocks can be left blank.
Rating blocks
A required Rating block won't accept a submission of 0 (no rating selected). The respondent has to click a star/number to pass.
What respondents see
Validation errors appear inline below the offending field with red text. The page also scrolls to the first error on submit so the respondent doesn't have to hunt.
When to be lenient
Mark blocks as Required only when you genuinely can't act on the submission without that field. Over-requiring causes drop-off — especially on phone numbers and company names.