Frank Ripploh's autobiographical study of a homosexual teacher was first submitted to the BBFC in September 1981. The film focusses on the tension between the central character's professional life as a school teacher and his personal life in which he engages in gay sex with strangers, often in and around public lavatories (the film's title translates as 'Taxi to the Toilet').

The distributor indicated that their intention was to show the film in cinema clubs (to which members only were admitted and for which no BBFC certificate was required) and then, when club distribution was exhausted, to exhibit the film in commercial cinemas, for which a BBFC classification would be required.

The BBFC examined the film carefully, also seeking input from legal advisers including QCs. An extensive list of cuts was drawn up that would be required before an X certificate could be granted (mainly to remove sight of erections, penetration, whipping and close up sight of an anal examination). However, the BBFC also informed the distributor that its legal advisers had flagged up two scenes as potentially problematic, even if the film were shown without a certificate in members only cinema clubs.

These were:

(1) a scene - part of a genuine German public information film - in which a man appears to put his hand on a boy's knee and then place the boy's hand within his own trousers and

(2) another scene showing unsimulated urolagnia (urination onto another person during sex).

According to the Board's legal advisers, the first scene might fall foul of the recently introduced Protection of Children Act 1978 (which made it illegal to distribute indecent images of persons under 16) and the second scene might fall foul of the Obscene Publications Act.

These laws applied equally to club screenings and to screenings in public cinemas. Accordingly, the distributor cut these two scenes on the Board's advice before releasing the film (without a certificate) in cinema clubs. However, given the extent of additional cuts required to obtain an 'X' classification for national distribution, the distributor decided not to proceed with formal BBFC classification at that time.

In 1982, the Local Government (Miscellaneous Provisions) Act was introduced. Amongst other things, the purpose of the legislation was to close down the existing loophole that allowed members only cinema clubs to exhibit films without the permission of the relevant local council or the BBFC. In future, any cinema club would have to be licensed by the relevant local authority and exhibit only films permitted by the Council or by the BBFC.

Given the specialised and self-selecting membership of such cinema clubs it was recognised that films shown in such clubs might legitimately be more explicit than those permitted in a public cinema, although what was shown would still have to remain within the law. In accordance with this, the BBFC introduced a new classification of R18 (Restricted 18) in 1982 which would allow more explicit material than what was permitted in the X category (simultaneously renamed the 18 category), provided that the film was shown only in licensed clubs.

The intention was that the new category would allow 'sex' films to be shown in sex clubs, such as those in Soho, as well as allowing more explicit material than usual to be shown in more serious cinema clubs. The effect of this legislation was that, from 1983, it would be necessary for Taxi Zum Klo to obtain an R18 certificate if it were to continue screening in cinema clubs.

Initially the BBFC had felt that it would be possible to pass the more graphic sexual material in the film at R18. However, discussions with the relevant enforcement agencies quickly showed that any sight of unsimulated sex was likely to be considered obscene under the Obscene Publications Act. Accordingly, when the film was resubmitted to the BBFC in 1983 in order to obtain an R18 classification, the BBFC had little alternative but to offer a long list of cuts similar to that originally demanded for an X classification.

Although some of the more borderline material (such as the whipping) was allowed to remain at R18, all sight of erections and sexual penetration would have to be removed. However, given that the film had already been showing in club cinemas for over a year without legal intervention, neither the film's distributor nor its director could understand the need for additional cuts. Therefore the film was withdrawn altogether from the classification process and from club cinemas. In the meantime, the film had been released on VHS in its marginally cut club version and remained available on video, nearly uncut, until after the introduction of the Video Recordings Act in 1984.

Subsequent to the introduction of the Video Recordings Actin 1984, Taxi Zum Klo vanished from the shelves of video shops and from the repertoire of licensed cinema clubs. Contrary to the original intention of club licensing, it was found that only sex films (as opposed to 'arthouse' films) were commercially viable in a club environment and that the prohibition on more explicit material at the R18 category (under the terms of the Obscene Publications Act) ultimately led to the death of cinema clubs in favour of illegal distribution on the more convenient medium of VHS.

In 1994, Taxi Zum Klo was formally submitted for video classification. On this occasion, the distributor was more amenable to cuts and cuts were therefore made to remove the material that had proven legally problematic in 1981 as well as to the more explicit sexual and genital detail. Ultimately the film was passed 18 for video release after one minute 43 seconds of cuts. Subsequent to this, the film was submitted for video classification by Film Four Channel in 2005.

According to Ofcom rules, Film Four were not allowed to show uncut versions of films that had been cut by the BBFC. However, if the BBFC would pass the film uncut according to contemporary standards - and this could be demonstrated by resubmitting the film to the BBFC - it would be possible to screen the film.

On this occasion the BBFC decided that the explicit sexual and genital detail was no longer problematic at 18, particularly given the precedents of Romance, The Idiots, In The Realm of the Senses and 9 Songs. Given that explicit sight of real sex had been passed at 18 in those films it would be indefensible to require cuts in the case of a similarly serious and worthwhile film. The explicit images were justified by the wider content of the film, which comprised a serious and compassionate examination of one man's sexual life and the tensions this created. In terms of the other material previously censored (even for club screenings) the BBFC similarly felt that legitimate arguments could be made for their retention.

With regard to the urolagnia, it was noted that the Obscene Publications Act required that a work should be considered as a whole and that, taken as a whole, Taxi Zum Klo was unlikely to be found obscene. Whereas a sex work with similar material might be found to be in breach of the law, the fact that Taxi Zum Klo had a different purpose to a 'sex work' (ie its purpose was not merely to sexually arouse) meant that, as an illustration of a particular lifestyle (rather than an attempt to 'sell' or eroticise that lifestyle), it was unlikely to render the work as a whole obscene.

With regard to the Protection of Children Act, the BBFC investigated the origins of the public information film included in Taxi Zum Klo and managed to obtain assurances from the relevant German educational authorities that no child had been mistreated in the making of that film. In fact, an adult woman had been used in the close shots showing hands on thighs and a hand entering a man's trousers. So there was no breach of the Protection of Children Act. Accordingly, Taxi Zum Klo was passed '18' uncut in 2005, albeit only for television screening. 

In 2011, Taxi Zum Klo was resubmitted to the BBFC for a cinema and DVD re-release and was passed 18 uncut, with all previous cuts waived.