Format, the B1 rule, and each part are on the DTZ B1 page.
Quick Answer
g.a.s.t. states you can retake the DTZ without a fixed cap, but every attempt is the complete exam: written and oral parts together, with no banked scores from a previous sitting. Paying out of pocket for another full registration is always an option for eligible candidates. Whether BAMF funds another Integrationskurs block or exam-related support is a separate administrative question — after the Integrationskurs regulation change, funded repeats of course hours are limited to alphabetisation courses and courses for learners with special pedagogical need; do not present that as a universal free retake. Read the BAMF Abschlussprüfung page for the wording that actually binds course participants, and stay within what it says.
No partial carry-over
Plan finances and calendar as a full rerun. Strong Hören/Lesen from last time still helps your study plan, but the certificate process starts from zero on registration day.
Inspecting papers (Einsicht)
Within three months of receiving your result you may apply to inspect your work. Processing can take up to eight weeks. Viewings are usually on the second Wednesday of the month at fixed Prüfstellen in Chemnitz (09111), Berlin (10777), Wedel (22880), Hildesheim (31134), Dortmund (44137), Bingen am Rhein (55411), Augsburg (86199), and Nürnberg (90441), for about fifteen minutes. You may see your Lesen and Hören answer sheets, your Schreiben sheet, and the oral mark sheet — not the confidential tasks or solutions. That inspection network is unrelated to where you first sat the exam.
Naturalisation language proof
Which certificate authorities accept, and how old it may be, sits outside this retake article. Use Germany naturalisation language certificates for exam choice, and avoid recycled claims about residence years tied to the Integrationskurs certificate — those lines belong to legal advice, not to a language-exam retake note.
Route the next attempt through the learning path
Open the Prep2Go DTZ B1 learning path to stack listening, reading, writing, and paired-speaking work with the official clocks — especially if the last fail was a time-management problem rather than vocabulary breadth alone.